Obama supporters are more excited

That smiling guy walking down the street? Odds are he's a Barack Obama backer. The grouchy looking one? Don't ask, and don't necessarily count on him to vote, either.

Supporters of John McCain, long less enthusiastic than Obama's, have become increasingly glum about the presidential campaign in recent weeks, according to an Associated Press-Yahoo News poll released Saturday. Their feelings have turned more negative during a period that has seen Obama take a firm lead in many polls.

Obama's backers have retained a higher level of excitement. One expert says the contrasting moods could affect how likely the two candidates' supporters are to vote on Election Day, possibly dampening McCain's turnout while boosting Obama's.

While 43 percent of Obama's backers said they are excited over the campaign, just 13 percent of McCain's said so, according to the survey of adults, conducted by Knowledge Networks. Six in 10 Obama supporters said the race interests them, compared with four in 10 backing McCain.

On the flip side, 52 percent of McCain supporters said the campaign has left them frustrated, compared with 30 percent of Obama's. A quarter of McCain backers say they feel helpless, double the rate of those preferring Obama.

Obama leads McCain among likely voters in the AP-Yahoo News poll, 51 percent to 43 percent.

The AP-Yahoo News poll of 1,753 adults was conducted Oct. 17-27 and had an overall margin of sampling error of plus or minus 2.3 percentage points.