Traditionally, married men are a strong Republican group; single women, core Democrats. In 2000 their opposites -- single men and married women -- divided evenly between Gore and Bush. This year, instead, Bush is winning married women by 53 percent to 44 percent, while Kerry is winning single men, by 56 percent to 41 percent.
Other groups are dividing among customary lines. Kerry leads by 86 percent to 10 percent among blacks, one of the core Democratic groups, and by 63 percent to 36 percent among Hispanics. Evangelical white Protestants, core Republicans, split 76 percent to 22 percent for Bush.
As noted, Bush is doing better in his base, with 91 percent support from Republicans, and pulling 13 percent of Democrats from Kerry; Kerry gets 8 percent of Republicans. Poaching from the other side may be somewhat easier for Bush because there are three times as many conservative Democrats as there are liberal Republicans.
It's not solely about partisanship -- a key difference between now and 2000 is that Kerry leads among independents in this poll, while in 2000 they split 47 percent to 45 percent, Bush-Gore. But the partisan makeup of tomorrow's electorate still is likely to be a critical factor. Democrats outnumbered Republicans by three or four points in each of the last four presidential elections, and the ratio translates directly to votes.
Whatever the result, this close election -- like the last -- could well be a sign of things to come. ABC News polls over the last 23 years have shown a gradual but unmistakable closing of the partisan gap; among all Americans, where there once were steadily more Democrats than Republicans in this country, there are now about equal numbers of both. That could be reflected in Election Day turnout; in any case, the slow trend suggests a close division in partisanship -- and thus in national elections -- for years to come.
Finally, the election promises to be historic in any number of ways, but here are two: No president since Harry Truman with a job approval rating under 50 percent the summer before the election has been re-elected; Bush was at 47 percent in June, and right on the bubble, 50 percent, in a tracking result two weeks ago.
At the same time, no incumbent running for re-election since 1956 has lost when consumer confidence was above its long-term average; and confidence today, while hardly brimming, is above average.
Therefore this either will mark the first time since Truman that a less-than-popular president has been re-elected; or the first time since Eisenhower that an incumbent's been thrown out when consumer confidence was better than usual. No such precedent is predictive -- and one of these will not survive the 2004 election.
This poll was conducted by telephone Oct. 28-31 among a random national sample of 4,009 adults, including 3,511 registered voters and 2,904 likely voters. The results have a two-point error margin for the likely voter sample. Sampling, data collection and tabulation was done by TNS of Horsham, Pa.
See previous analyses in our Poll Vault.