As voters head to the polls, the conventional wisdom states that red wave will wash over the United States. While political statistician extraordinaire Nate Silver concluded a Republican takeover of the Senate is unlikely, he estimates GOP gains in the House could reach 55 seats. That's in line with a 50-60 pick-up forecast by Charlie Cook. But the extent of the carnage for Democrats hinges on the much-hyped "enthusiasm gap." And the early, if anecdotal, evidence of strong voter turnout suggests that may not be coming to pass as predicted.
That at least is the word from locations around the country. In a round up of early voting, the Huffington Post reported "shocking" turnout. In Massachusetts, "State and local election officials were already predicting possibly record voter turnout today." In Pennsylvania and Louisiana, too, larger than expected numbers of voters are arriving to cast ballots. At one St. Louis polling place, "election judges said the first two hours had been just as busy as two years ago, when voters formed long lines to cast a ballot in the presidential election."
If so, that would be a surprise, and a welcome one for Democrats. As the data show, over the last decade voter turnout in midterm elections has been as much as 20 points lower than in presidential contests.
Based in part on early voting results so far, the United States Election Project forecasts a 2010 nationwide turnout of 41.3%, the same level when Democrats regained control of the House and Senate in 2006. In absolute numbers, that would nevertheless represent a new record:

Dr. Michael McDonald, who tracks election turnout at George Mason University, projects that a record-breaking 90 million people will cast ballots for 2010 candidates, the largest number of voters to date in a midterm election.
The current midterm record was set in 2006, when 86 million voters went to the polls.

Still, that turnout probably wouldn't be enough to produce happier alternative scenarios for Democrats of the kind envisioned by Nate Silver of HuffPo's Mark Blumenthal. (After all, the Republican Revolution of 1994 saw turnout at 41.1%.) Final polling shows a Republican lead among likely voters ranging from 1 point (NBC/Wall Street Journal) to 15% (Gallup). That gap virtually disappears among registered voters, as the Gallup (R+4) and NBC (D+3) surveys reveal. To overcome the GOP edge, President Obama's party likely needs the share of eligible voters casting ballots to reach 43% or higher.
For Democrats hoping to avoid a midterm bloodbath, that is probably the last, best hope.