As ABC News helpfully reminds us, April 15th is John McCain Tax Flip-Flop Day. McCain, as you'll recall, twice voted against President Bush's budget-busting tax cuts for the richest Americans who need them least. But having undergone a supply-side conversion on the road to the White House, John McCain now wants to make them permanent.
John McCain's gymnastic flip-flop on the Bush tax cuts ranks among his greatest acts of political contortion. What he once opposed as fiscal recklessness and a massive giveaway to the wealthiest Americans, McCain now backs as the price of admission to the Republican presidential nomination.
As the laissez-faire zealots at the Club for Growth detail, McCain is proof that evolution is reversing when it comes to the Bush tax gambit. In June 2001, McCain rightly proclaimed his opposition to Round 1 of President Bush's treasury-financed redistribution of wealth:

"I cannot in good conscience support a tax cut in which so many of the benefits go to the most fortunate among us at the expense of middle-class Americans who need tax relief."

By December 2007, however, that message sounded more like John Edwards than Ronald Reagan, so candidate John McCain needed a different rationale. Asked by the National Review's Rich Lowry on Fox News if he thought it had been a mistake to vote against the Bush tax cuts in 2001 and 2003, McCain claimed in the name of fiscal discipline he would do it all again:

"No, because I had significant tax cuts, and there was restraint of spending included in my proposal. I saw no restraint in spending. We presided over the greatest increase in the size of government since the Great Society. Spending went completely out of control. It's still out of control. Wasteful earmark spending is a disgrace, and it caused us to alienate our Republican base."

Of course, the spending cuts never came from the Bush White House or the Republican Congress. But with a presidential bid in the offing, McCain decided the third time was a charm. Facing opposition on his Republican primary tightrope walk from Rudy Giuliani ("John voted against the Bush tax cuts, I think on both occasions, and sided with the Democrats") and others, McCain simply did an about-face.
As Tim Russert noted on January 6th, McCain not only voted for the budget busting tax cuts the third time around, but now believes they should be made permanent:

SEN. McCAIN: ...unless we cut spending then, then we are going to end up in a - the serious situation we're in today. I will cut spending. And I will continue to support making the tax cuts permanent, which I've voted already twice.
MR. RUSSERT: But you voted the third time for the tax cuts, but there weren't spending cuts.
SEN. McCAIN: Mm-hmm, mm-hmm. No, but I thought that we ought to keep the tax cuts permanent because if we had increased taxes, which that would have had the effect of, if I had voted in the other way...

In his book, The Big Con, Jonathan Chait summarized John McCain's conversion from supply-side apostate to tax-cutting zealot. In 2000, Jack Kemp proclaimed of McCain's 2001 opposition to the Bush tax cuts, "John McCain, who's a friend of mine, has done a - has made a huge mistake." By 2006, McCain had drunk the Koolade and signed on supply-side godfather Arthur Laffer to his economic team. By 2007, he mouthed the party line, "tax cuts, starting with Kennedy, as we all know, increase revenues."
And that kind of talk makes anti-tax crusader Grover Norquist very happy indeed. Norquist, who once called McCain "that nut-job from Arizona," now praises McCain for adopting "the Americans for Tax Reform's entire agenda." As ABC reported today, Norquist can hardly contain his glee when it comes to John McCain's shocking reversal on the Bush tax cuts:

"Why am I happy on taxes?" Norquist told ABC News. "Because he has endorsed and put out the four tax cuts that A.T.R. considers the key ones: expensing, cutting the corporate [tax] rate, extending the 2001 and 2003 [Bush] tax cuts, and getting rid of the A.M.T. [Alternative Minimum Tax.
"And he has said three times on national T.V., 'I'll veto any tax increase, end of conversation,'" added Norquist.

All of which means that a President John McCain would preside over a budget-busting redistribution of wealth in the U.S. that would make George W. Bush look like Karl Marx.
As ThinkProgress meticulously detailed, McCain has thrown budgetary caution to the winds in a proposal that even his top economic adviser admitted " will make deficits expand up front:"

Our analysis suggests that the McCain plan shares five key characteristics of Bush policies. First, it is enormously expensive, costing more than $2 trillion over the next decade and essentially doubling the Bush tax cuts. Second, the McCain plan would predominantly benefit the most fortunate taxpayers, offering two new massive tax cuts for corporations and delivering 58 percent of its benefits to the top 1 percent of taxpayers. The Bush tax cuts provide 31 percent of their benefits to the top 1 percent of taxpayers.
Third, the McCain tax plan continues the shift of the tax burden from investment income onto earned income. Fourth, the plan not only fails to address current tax shelter problems in the tax code but in fact will lead to increased sheltering. Fifth, McCain cannot pay for his tax cuts without massive reductions in Social Security, Medicare, or other key programs that benefit the vast majority of Americans.

So this April 15th, be sure to commemorate John McCain Tax Flip-Flop Day. (Since you still can't read about John McCain's yet-to-be released tax returns, you can read about his tax proposals) After all, if John McCain is elected President, your children will be paying for it for years to come.
(For more history on other of John McCain's myriad flip-flops and turnabouts, see "From Maverick to Prostitute: The Untold Story of John McCain.")