First-time voters underscore Barack Obama's organizational advantage in the presidential election: Four years ago first-timers backed Democratic nominee John Kerry by 7 points. Today they favor Obama over John McCain by 47.
Indeed it's first-timers who give Obama his clear advantage in presidential preference.
Among people who've voted previously, Obama and McCain are at 50-47 percent in this ABC News/Washington Post poll, not a statistically significant gap. But first-time voters favor Obama by a lopsided 73-26 percent, lifting him to an overall advantage.
There are striking vote-preference differences among other groups, many well-examined in the contest so far -- young voters vs. their elders, whites and blacks, "economy" voters vs. those more focused on other issues -- and others less so.
First-time voters are among the telling ones; they attest both to the Obama campaign's efforts to sign up new voters, and to the extraordinary level of enthusiasm among his supporters this year.
But there's a cautionary note for the Obama campaign: Turnout among first-time voters is challenging to predict, since they're clearly not in the habit.
That means targeted get-out-the-vote efforts can matter particularly with this group -- not just in how many vote, but in how those who do vote divide between the candidates.
Overall, two weeks before Election Day, Obama leads McCain by 53-44 percent among likely voters, unchanged from yesterday's tracking results. Obama's held the advantage since taking a clear lead on the strength of economic discontent in an ABC/Post poll on Sept. 22.
First-time voters account for 11 percent of all likely voters in this poll, matching their turnout in the 2004 presidential election.
According to the national exit poll that year, they voted 53-46 percent for Kerry vs. George W. Bush, a far narrower division than their vote preference today. (Bush won previous voters by 51-48 percent.)
Naturally, first-time likely voters are predominantly young, long Obama's best support group; 69 percent of them are under age 30. But young voters, in particular, can be skittish in terms of turnout.
First-time likely voters this year include three times as many Democrats as Republicans, a sharp shift from 2004, when partisanship was about even among first-timers. Given their youth, a third of likely first-time voters are liberals, vs. a quarter in 2004 (and more than among repeat voters this year, 20 percent).
Another difference among groups is based on where likely voters live: Obama leads by 30 points among city dwellers, but it's McCain by 23 points among rural Americans. Suburbanites divide almost exactly evenly.
Obama leads overall partly because of his slightly larger advantage among urban voters (64-34 percent, compared with McCain's 59-36 percent among rural voters), but also because there simply are more of them: Twenty-five percent of voters are urban, vs. 16 percent rural.
Divided suburbanites constitute the plurality, 46 percent of voters, splitting 48-47 percent between Obama and McCain.