As the 2020 election season heats up, voters’ priorities are coming into sharper focus. As in years past, there is a great divergence in what each party ranks as its top issues. Earlier this year, the Pew Research Center found that Republicans identify terrorism, the economy, Social Security, immigration, and the military as their five greatest concerns. Democrats prioritize health care, education, the environment, Medicare, and the poor and needy above all. According to a Gallup poll in April, Democrats responded that addressing “government/poor leadership” was Job #1, while GOP backers said immigration was the nation’s most important problem.

Nevertheless, that doesn’t mean there is unanimity across the Democratic base about either what to do or how to get it done. An April survey by Morning Consult, for example, revealed that Biden supporters put “seniors’ issues” atop their concerns, while health care rated first for backers of Sens. Bernie Sanders and Elizabeth Warren. And to be sure, the increasingly heated debates over the meaning and wisdom of policy proposals including “Medicare for All,” the “Green New Deal,” free college education and “decriminalization” of the border are producing sharp cleavages among Democratic Party activists. The result on Facebook, Twitter, and across social media is a war of words between the #BlueNoMatterWho crowd and those threatening to withhold their votes in November 2020 from any Democratic nominee they deem too “corporate” or “establishment.”

But while the party’s most energized supporters do battle over, say, the elimination of private health insurance or taking contributions from fossil fuel companies, Democrats may be missing the forest for the trees. That’s because in 2020, the single-most important domestic issue facing Democrats is the make-up of the federal courts. For all intents and purposes, nothing else comes close. If Donald Trump’s extreme makeover of U.S. district courts, appellate courts, and the Supreme Court is not halted and reversed, it won’t just be women’s reproductive rights and marriage equality facing immediate jeopardy. As recent decisions from Roberts Court and trends in conservative jurisprudence at all levels of the federal judiciary increasingly make clear, the entire legal framework for post-New Deal government in America is facing an existential threat.

To understand why, it’s essential to first grasp the magnitude of the conservative victory in its conquest of the judicial branch. The GOP’s multi-decade, multi-pronged strategy has delivered a production line of right-wing jurists recruited and groomed by the Federalist Society and other conservative organizations, all ready to be slotted into the seats left vacant by the Republicans’ unprecedented obstruction of Democratic presidents.

As I documented in February 2017 in “Judge Not, Lest Ye Be Judged,” the GOP blockade of President Obama’s judicial nominees was near. Using filibusters, “blue slips” and other obstructionist tactics, Senate Minority Leader Mitch McConnell ensured only 43% of Obama’s picks to district and appellate courts made it through the confirmation process during his first 14 months in office, less than half the 87% rate Republican George W. Bush achieved over the same period. By the next year, Obama’s success rate improved to 58%, but still badly lagged his predecessors from either party going back to Jimmy Carter. All of this was during a time when the Democrats maintained a Senate majority. By 2013, then-Senate Majority Leader Harry Reid (D-NV) had no choice but to go “nuclear” and change Senate rules to end the filibuster on non-Supreme Court nominations. Nevertheless, over Barack Obama’s last two years in office, only a paltry 28 of his selections made it to their seats on the bench. As McConnell explained to Hugh Hewitt in June 2015, those few successes came only in those cases where two home state GOP senators blessed the selection:

“So far, the only judges we’ve confirmed have been federal district judges that have been signed off on by Republican senators,” McConnell said on “The Hugh Hewitt Show.”

“And do you expect that that will continue to be the case for the balance of this session?” Hewitt asked.

“I think that’s highly likely, yeah,” McConnell responded.

And that was before the 2016 death of Justice Antonin Scalia and the hostage-taking of Merrick Garland. As Leader McConnell boasted in August 2016:

"One of my proudest moments was when I told Obama, 'You will not fill this Supreme Court vacancy.'"

Not that vacancy and not dozens of others. When Barack Obama left the White House on January 20, 2017, there were 103 vacant federal judgeships, nearly double the 54 George W. Bush left unfilled 8 years earlier.

Of course, with Republican Donald Trump in the White House, the McConnell rules quickly went the way of the dodo. To grease the skids for Trump’s choice Neil Gorsuch into the Garland seat, McConnell killed the filibuster for Supreme Court nominees. As his direction, the GOP has ceased following the “blue slip” rule, last week confirming Daniel Bress to the 9th Circuit Court of Appeals despite objections from home state Sens. Kamala Harris and Dianne Feinstein. As for the notion that no nominee will be confirmed to the Supreme Court in a presidential election year, Mitch McConnell in May made clear that only applies when a Democrat is in the White House.

In stark contrast to Barack Obama, Donald Trump has enjoyed watching a conveyor belt of judicial nominees rapidly deposited into seats at all levels of the federal judiciary. Screened by the Federalist Society’s Leonard Leo and shepherded through the Senate by McConnell, Trump’s picks are quickly altering the balance on the bench. On February 14, 2017, Josh Katz of the New York Times looked at the federal open seats and the share of “senior” judges before concluding, “Trump could fill more judicial vacancies than any first-term president in decades.” A year ago, the Washington Post explained that the wave of new Trump judges wasn’t a record per se, but certainly was for the nation’s circuit courts of appeal. By September 2018, Kevin Schaul and Kevin Uhrmacher of the Washington Post showed, Trump easily shattered the mark for filling the appellate courts, more than doubling the number of circuit court judges President Obama had elevated at the same point in his tenure.

Arthur D. Hellman, a University of Pittsburgh law professor who studies the federal judiciary, summed up why that development is so important for the future:

“The Supreme Court gets the bulk of the attention, but the circuit courts decide the bulk of the cases. Because the Supreme Court these days is taking so few cases, the law of the circuit is, on many, many issues, the final law for the people who live in that circuit.”

By May 2019, the Trump judges numbered over 100, including 40 on the circuit courts of appeal. By the story of Trump’s transformation of the bench is about much more than numbers. “As a group,” the Washington Post documented, “the new judges are indeed whiter, more male and more conservative than recent presidents’ nominees.” Make that “much more conservative.” As Vox reported in January:

President Donald Trump’s judicial appointees are more conservative, on average, than those nominated by former Republican presidents, according to a new study commissioned by the liberal activist group Demand Justice.

The study, which was conducted by progressive think tank Data for Progress, found that Trump judicial appointees were, on average, 20 percent more conservative than George W. Bush’s.

The result has been an expansion of the strong Republican slant of several circuit courts, while narrowing or eliminating the Democratic advantage on others. In May, Russell Wheeler of the Brookings Institution tallied up the impact of Trump’s “bulldozer efficiency” in re-leveling the appellate courts:

Only the 3rd U.S. Circuit Court of Appeals has flipped from a Democrat-appointed majority to a Republican one during Trump’s tenure, but “the Trump circuit appointments have strengthened Republican-appointee majorities on four courts that already had such majorities — those of the 5th, 6th, 7th, and 8th circuits,” according to Wheeler.

Even the legendarily liberal 9th Circuit Court presiding over nine western states is experiencing an extremist makeover. In April 2018, only six of its 29 active seats had been chosen by Republican presidents. A year later that number jumped to 13. GOP activists are itching to take down Donald Trump’s judicial bogeyman. As Adam Feldman of Empirical SCOTUS blog told Fox News:

"As the 9th Circuit shifts to become more conservative and better parallels the Supreme Court's ideological baseline, I could only imagine fewer liberal 9th Circuit decisions and fewer overturned 9th Circuit decisions generally.”

And to be sure, that ideological baseline has already changed greatly under Donald Trump. In four more years under GOP control of the White House and the Senate, that baseline—and perhaps American government itself—would be unrecognizable to most citizens of the United States.

Consider just some of the Supreme Court rulings in recent years already shifting the legal ground under Americans’ feet. In the Shelby County and Northwest Austin Municipal Utility cases, Chief Justice John Roberts realized his 30-year goal of gutting the vital “pre-clearance” provisions of the Voting Rights Act. Citizens United washed away critical limits on federal campaign contributions and ushered in a new era of “dark” money. In the 2012 NFIB v. Sebelius case, despite narrowly preserving Obamacare, John Roberts confounded most analysts by ruling that the Affordable Care Act’s individual insurance mandate could not be justified using under Congress’ Article I Section 8 “Commerce Clause” power. Just as ominous, in Hobby Lobby Justice Samuel Alito ruled the First Amendment and the Religious Freedom Restoration Act (RFRA) meant the federal government could not “substantially burden religious exercise” of a closely held private business. And by a 5-4 vote, Obergefell v. Hodges made marriage equality the law of the land, a result made possible by former Justice Anthony Kennedy’s understanding of the 14th Amendment’s Due Process and Equal Protection clauses (and, arguably, the influence of his gay mentor).

Oh, and one other thing. Anthony Kennedy is gone. Neil Gorsuch and Brett Kavanaugh are on the Supreme Court. And waiting in the wings on Donald Trump’s short list for the next opening on the Court are some of the most reactionary jurists in the United States today.

It is into this right-wing maelstrom that the huge field of 2020 Democratic presidential candidates is bringing the most ambitious domestic policy agenda since FDR and the New Deal. Taken together, proposals like Medicare for All, the Green New Deal, election reform, subsidized childcare, student debt forgiveness, free college, and more represent the greatest expansion of the role of government since Lyndon Johnson’s Great Society programs of the 1960s. And like the conservative Supreme Courts of the Progressive Era and the early New Deal, a growing, retrograde right-wing judicial branch is poised to stop this new movement dead in its tracks.

Consider, for example, the various proposals to enable universal health care in the United States. As of this writing, the Fifth Circuit Court of Appeals seems poised to strike down the entirety of the Affordable Care Act under the preposterous theory that (a) without a penalty or “tax,” the individual mandate is unconstitutional; and (b) the mandate is somehow not “severable” from the rest of the law, meaning all of Obamacare must be struck down. That this wasn’t the case in 2012, when the original Medicaid expansion was invalidated but nothing else, doesn’t seem to matter to that GOP-dominated bench.

Even if Obamacare survives this latest Republican attempt to extinguish it, would-be Democratic replacements will soon come under immediate challenge. Bernie Sander’s proposed to eliminate the private insurance industry will doubtless be met with claims that the Commerce Clause does not empower Congress to sentence entire classes of companies to extinction. Just as important, any plan to reduce health care spending through government price-setting for physicians, clinics, medical devices, hospitals, tests, pharmaceuticals will undoubtedly end up in court as well. And within the ranks of acceptable conservative jurisprudence are “zombie” legal theories which will be resurrected precisely for those purposes.

As Jeffrey Rosen, Brian Beutler and Ian Milhiser have explained, a growing “rehabilitationist” movement within conservative legal circle is seeking to undermine the entire legal framework that has made American government since the New Deal possible. Targeting what they charge is a baseless expansion of the meaning of the Commerce Clause, they claim to represent the “Constitution in Exile.” As Bush SCOTUS short-lister Janice Rogers Brown famously put it:

“The Constitution itself was transmuted into a significantly different document...1937...marks the triumph of our own socialist revolution.”

What Rogers Brown is decrying is 75 years of Supreme Court precedent dating back to Roosevelt’s second term which, among other things, upheld much of the New Deal, Social Security, Medicare, and the expanded executive branch. One of the key tools for doing so, they argue, is to reanimate the 1905 Lochner standard. Often mocked in the same sentence with Dred Scott and Plessy, Lochner was among the most sinister cases in American history. As Milhiser explained, Lochner struck down a New York law limiting the work day for bakers who routinely labored where "sewage pipes leaked raw contents" in rat-infested "hot dungeons heated by lit ovens," the Supreme Court invented a new fundamental right, the "right of contract":

Though New York enacted a law limiting bakers' hours to 10 a day and 60 per week, a 5-4 Court struck this provision down in Lochner, resting the decision on a so-called "right to contract" that it read into the Fourteenth Amendment. The "right to contract" was, essentially, a right to be bound by nearly any contract a worker agreed to, no matter how desperate the circumstances or how uneven the bargaining power that forced them to agree to such a deal. Thus, if New York bakers agreed to work 14 hours a day, seven days a week, the state had no authority to take that "right" away from them.

Other decisions relying on this "right to contract" used the Fourteenth Amendment to strike down minimum wage laws and laws preventing union busting.

Judges like Texas State Supreme Court Justice Don Willett, Kentucky Senator Rand Paul, and groups like the Goldwater Institute and the Institute for Justice want to resurrect long-discarded notions of the freedom of contract, a restricted commerce clause and “substantive due process” under the 14th Amendment. If they succeed, Rosen argued back in 2005, reactionary federal courts “could change the shape of laws governing the environment, workplace health and safety, anti-discrimination, and civil rights, making it difficult for the federal government to address problems for which the public demands a national response.”

But the potential legal crisis facing progressive policymakers is even more dire than that. In last month’s Gundy decision, an 8-member Supreme Court (Brett Kavanaugh did not participate) led by Justice Elena Kagan upheld the applicability of a national sex offender registry to 500,000 people convicted before its passage. In her majority opinion, she ruled that the legislation in question did not violate the “nondelegation doctrine,” a principle that Congress may not shift too much legislative power to another branch of government. (That principle has only been used successfully twice, both in 1935 to strike down New Deal laws.) As Kagan explained, the law provided an “intelligible principle” that Congress wanted the registry made retroactive when the attorney general deemed it practicable. “That delegation,” she wrote, “easily passes constitutional muster.” Besides, she explained:

“[I]f SORNA’s delegation is unconstitutional, then most of Government is unconstitutional—dependent as Congress is on the need to give discretion to executive officials to implement its programs.”

Which is exactly the point the furious conservatives wanted to make. Though voting with the majority in this narrow 5-3 ruling, Justice Samuel Alito made it clear where he stood. As Mark Joseph Stern summed up Alito’s position:

Justice Samuel Alito provided the fifth vote to uphold the law, but did so begrudgingly. “If a majority of this Court were willing to reconsider the approach we have taken for the past 84 years,” Alito explained, “I would support that effort. But because a majority is not willing to do that, it would be freakish to single out the provision at issue here for special treatment.” In other words, Alito isn’t going to break 84 years of precedent to the benefit of a half-million sex offenders.

In his dissent, Justice Neil Gorsuch went further still, condemned the “intelligible principle” rule as a “misadventure.” Exhuming the nondelegation doctrine buried with Cro-Magnon conservative court in 1935, Gorsuch scorning “a plurality of an eight-member Court” for ignoring “the Constitution’s demands.” Were Gorsuch’s view to prevail, his new standard would take a wrecking ball to much of the federal government:

Gorsuch’s fuzzy new rule would work a revolution in federal law. Hundreds of statutes task the executive branch with some broad goal, then let agencies fill in the details. The Environmental Protection Agency, for instance, has wide latitude to identify and restrict pollutants, because Congress doesn’t want to legislate every new regulation. Instead, it gives the EPA certain guidelines, then leaves it to the agency’s scientists to determine what rules would best serve the public. The same goes for the Department of Labor, whose experts are empowered to identify and remedy workplace abuses.

There’s little doubt where Justice Brett Kavanaugh stands on these questions. As Pema Levy warned in “How Brett Kavanaugh Could Cripple the Next Democratic President” a year ago:

Two words: Chevron deference.

During Kavanaugh’s confirmation process, SCOTUSBlog detailed the essential role that the “Auer Deference” and “Chevron Deference” make in enabling executive branch agencies to make administrative rules according their interpretation of federal law. As Levy explained:

Developed in a 1984 Supreme Court decision, Chevron is a framework judges use in determining whether the rules and actions of executive branch agencies are consistent with laws that have been passed by Congress. The modern administrative state promulgates thousands of rules each year, as highly specialized regulators work to implement congressional legislation that is often imprecise or unclear. That makes Chevron a key precedent shaping everything from health care to technology to the environment…

Under Chevron, the courts defer to a federal agency’s interpretation of a statute when the law’s language is ambiguous and the agency’s interpretation is considered reasonable. Chevron therefore allows agencies to implement rules and regulations, even when the statutes—often vague—do not obviously call for them, or when judges would have personally interpreted the law differently. Part of the logic is that agencies, which build up expertise on the complex issues they regulate, are better positioned than judges to create workable rules.

But Gorsuch, Kavanaugh and a large slice of the conservative legal system are no fans of Chevron. “The Chevron doctrine encourages agency aggressiveness on a large scale,” Kavanaugh scoffed, “Under the guise of ambiguity, agencies can stretch the meaning of statutes enacted by Congress to accommodate their preferred policy outcomes.”

When Steve Bannon talked about the “deconstruction of the administrative state,” this is precisely what he had in mind.

Imagine turning back the legal clock by a century in the United States and then trying to implement, say, the Green New Deal. Whether the version is from Alexandra Ocasio-Cortez, Jay Inslee, Elizabeth Warren or anyone else, success is virtually impossible without Democratic control of the courts.

And so it goes on issue after issue. For example, fighting back against the massive GOP voter suppression machine is an obvious priority for any Democratic president. But the Roberts’ Court has gutted the Voting Rights Act, blessed voter ID laws in states like Indiana, and declared in the recent Rucho and Lamone decision that the courts have no role in addressing even the most grotesque partisan gerrymandering of legislative districts. Dismantling the panoply of GOP disenfranchisement efforts is going to require Democratic victories at the ballot box and in courtrooms nationwide. Purges of voter rolls, limits on voting days and hours, limiting polling place locations, trying new voter identification schemes, attempting 21st century poll taxes, and even roadblocks to registration will all enjoy protection from Republican judges. Attempts to define congressional districts by the number of American citizens or even voting age population may be postponed, but they will be back.

Women’s reproductive rights, already in dire jeopardy, cannot withstand the assault of four more years of right-wing jurists. The head-on challenges to Roe v. Wade and Planned Parenthood v. Casey are coming. Republican judges are making a joke of the “undue burden” standard for protecting abortion access. Victories at the Supreme Court for so-called Pregnancy Resource Centers mean that anti-abortion forces may lie to women. At the same time, unless First Amendment triumphs come soon for doctors and other abortion providers, states will be able to mandate that physicians must lie to women about mythical abortion-cancer links, made-up “abortion regret syndrome,” and even the dangerous fiction of “abortion reversal.” Meanwhile, the Trump administration and states like Georgia seeking to enshrine a “Fetal Fourteenth Amendment” in law. That is, zygotes, embryos, and fetuses enjoy due process of law and equal protection of the law; actual, living American women apparently do not.

And certainly, neither will LGBTQ Americans, either, if a conservative federal judiciary takes the day. An expanded Republican SCOTUS majority would likely overturn Justice Kennedy’s Obergefell v. Hodges opinion on marriage equality. The Trump administration has made clear it will support states in rejecting workplace protections for gay Americans, limit their ability to adopt children and enjoy the same civil rights as straight Americans. The United States will soon be deciding whether or not the Civil Rights Act of 1964 applies to LGBTQ Americans. There is little doubt where conservatives will come down on those cases.

So, whether you back Bernie or Beto, plan to vote for Booker or Biden, believe Elizabeth Warren has a plan for that or think Mayor Pete has the answer, I ask you to think first about the courts. Think about the contributions of Elena Kagan and Sonia Sotomayor, the two justices Barack Obama put on the Supreme Court. (That would be the same Barack Obama some now call an “establishment” or “corporate” Democrat.) I’m confident that any of the horde of Democratic White House hopefuls will make judicial nominations we can be proud of, and not just live with. To those of my friends and political allies now telling me they “won’t be told who to vote for” or they will stay home in November 2020 if their candidate doesn’t get the nomination or isn’t “treated fairly,” I’ll just say this.

We’ve seen that movie before, and we know how it ends. As Politico recently described Donald Trump’s plan to whip up his base in 2020 by focusing on his judicial picks:

Trump’s team believes that stacking the judicial system with conservative judges galvanizes the base, demonstrates his ability to follow through on a 2016 campaign promise and will help win over crucial 2020 states like Colorado, Florida and North Carolina. And Trump himself is convinced that judicial appointments are central to both his legacy and policy agenda, as he has pushed for young judges who can serve for decades, according to former administration aides, close White House advisers and those familiar with the administration’s judicial plans.

In 2016, exit polls showed that a fifth of all voters claimed that the Supreme Court was their single-most important issue. Donald Trump easily beat Hillary Clinton by 56 to 41 percent. Republican voters got what they wanted; arguably it’s the only thing they’ve gotten from Donald Trump. The Democratic Party—and the United States of America, for that matter—can’t let that happen again in 2020.

This article first appeared at Daily Kos.