Washington The presidential race tightened after the final debate, with John McCain gaining among whites and people earning less than $50,000, according to an Associated Press-GfK poll that shows McCain and Barack Obama essentially running even among likely voters in the election homestretch.
The poll, which found Obama at 44 percent and McCain at 43 percent, supports what some Republicans and Democrats privately have said in recent days: that the race narrowed after the third debate as GOP-leaning voters drifted home to their party and McCain's "Joe the plumber" analogy struck a chord.
Three weeks ago, an AP-GfK survey found that Obama had surged to a seven-point lead over McCain, lifted by voters who thought the Democrat was better suited to lead the nation through its sudden economic crisis.
The contest is still volatile, and the split among voters is apparent less than two weeks before Election Day.
"I trust McCain more, and I do feel that he has more experience in government than Obama. I don't think Obama has been around long enough," said Angela Decker, 44, of La Porte, Ind.
But Karen Judd, 58, of Middleton, Wis., said, "Obama certainly has sufficient qualifications." She said any positive feelings about McCain evaporated with "the outright lying" in TV ads and his choice of running mate Sarah Palin, who "doesn't have the correct skills."
The new AP-GfK head-to-head result is a departure from some, but not all, recent national polls.
Obama and McCain were essentially tied among likely voters in the latest George Washington University Battleground Poll, conducted by Republican strategist Ed Goeas and Democratic pollster Celinda Lake. In other surveys focusing on likely voters, a Washington Post-ABC News poll and a Wall Street Journal-NBC News survey have Obama up by 11 points, and a poll by the nonpartisan Pew Research Center has him leading by 14.
Polls are snapshots of highly fluid campaigns. In this case, there is a margin of error of plus or minus 3.5 percentage points; that means Obama could be ahead by as many as 8 points or down by as many as 6. There are many reasons why polls differ, including methods of estimating likely voters and the wording of questions.
Charles Franklin, a University of Wisconsin political science professor and polling authority, said variation between polls occurs, in part, because pollsters interview random samples of people.
"If they all agree, somebody would be doing something terribly wrong," he said of polls. But he also said that surveys generally fall within a few points of each other, adding, "When you get much beyond that, there's something to explain."
The AP-GfK survey included interviews with a nationally representative random sample totaling 1,101 adults, including 931 registered voters and 800 adults deemed likely to vote. For the entire sample, the survey showed Obama ahead 47 percent to 37 percent. He was up by five points among all registered voters, including the likely voters.