It holds across other groups. Single women are a core Democratic group, but among those who are registered, just 49 percent say they're certain to vote.
Among registered Democrats overall, 59 percent say they're certain to vote, compared with 74 percent of Republicans. It's 61 percent among liberals vs. 70 percent among conservatives, and the spread grows to 63 percent among liberal Democrats vs. 80 percent among conservative Republicans.
Similarly, among 2008 Obama voters, 64 percent say they're certain to vote this year; among McCain voters, 79 percent. Among those who approve of Congress, 58 percent; among its critics, 67 percent. And among those who view the workings of government positively, 59 percent affirm that they'll vote; among its critics, 66 percent. (Add in people who've already voted and these differentials are about the same.)
Working-class white men (those with household incomes under $50,000) favored McCain by 8 points in 2008, and among registered voters they favor Republicans now by essentially the same margin. But among working-class white men who are most likely to vote, that swells to a 19-point gap, 56-37 percent for GOP House candidates.
And there's the Tea Party political movement. Overall it divides likely voters evenly; 43 percent support it, 43 percent are opposed. But among its opponents, 63 percent say they're certain to vote, while among its supporters, that's 73 percent. And among "strong" supporters of the Tea Party, albeit a small group, a remarkable 86 percent say they're certain to vote in this election.
Against all this the Democrats' ammunition is scarce. One edge is among union voters: People in union households are more apt than those in non-union households to say they'll certainly vote, 75 percent vs. 63 percent. And likely voters in union households are a pro-Democratic candidate group, by 54-42 percent. They voted for Obama by 59-39 percent in 2008.
GROUPS -- While turnout reigns, there's been some shifting in preferences as well. Obama won women by 56-43 percent; today they divide by 51-43 percent among registered voters -- and by 47-47 percent among likely voters. Obama won swing-voting unaffiliated voters (independents and others) by 52-44 percent two years ago. They now divide about evenly in House preference among registered voters, and favor Republicans by 50-41 percent among likely voters.
POLICY -- Perceptions of the Obama administration's approach to government are a factor as well, with Tea Party concerns resonating beyond the movement's ranks. Likely voters by nearly a 2-1 margin, 61-34 percent, say they favor smaller government with fewer services -- but by a vast 77-12 percent think Obama, by contrast, favors larger government with more services.
In another shift from 2008, by a 52-35 percent margin, more likely voters now worry that the Democrats will impose too many regulations than think the GOP will put in place too few of them. Two years ago this was reversed; more likely voters worried that McCain would impose too few government regulations than thought Obama would impose too many.
Judging the parties' approaches overall, likely voters divide about evenly on which they trust more to cope with the country's main problems: Forty-five percent pick the Republicans, 41 percent the Democrats -- a rare advantage for the GOP on this bottom-line measure.