Obama faces hurdles of his own. The poll shows lagging fervor for the Democratic senator from Illinois by supporters of his vanquished rival, Hillary Rodham Clinton. And there are lots of dispirited and undecided independents, who are expected to be pivotal on Election Day, now less then four months off.
The passion and interest shown by blocs of voters are important because they affect who will be motivated to vote. For now, the numbers favor Obama: 38 percent of his supporters say the election is exciting compared with 9 percent of McCain's. Sixty-five percent of Obama's backers say they are hopeful about the campaign, double McCain's, and the Democrat's supporters are three times likelier to express pride.
"Being African-American, you know, I do have some biases," said John Douglas, 67, of Villa Rica, Ga., an Obama supporter. He said the pride and thrill he feels about the possibility of the first black president "has been building up for my lifetime, it's been building up since the inception of our country."
Half of McCain's supporters say the race makes them frustrated, more than double Obama's backers who say so. By 2-to-1 or more, McCain backers are likelier than Obama's to say the campaign makes them bored, angry and helpless. And while 16 percent of those preferring Obama say they may change their candidate, 24 percent of McCain's say they might do the same.
"I don't feel I have a choice I can really get behind," said Carol Hall, 63, a Republican from Yorktown, Va., who prefers McCain but said he isn't conservative enough. But she doesn't trust Obama.
"I think they're pitiful choices."
The AP-Yahoo News poll, conducted by Knowledge Networks, has measured the political sentiments of the same 2,000 adults since November. While 45 percent expressed a great deal or quite a bit of interest in the campaign back then, 60 percent say so now, but it's Obama supporters whose energy has grown more: -More than twice as many Democrats as Republicans have gotten more excited about the campaign since the fall, 22 percent to 9 percent. Forty-seven percent of Republicans and 29 percent of Democrats express frustration.
-Blacks are three times likelier than whites to be more excited about the election than they were last fall, 33 percent to 11 percent. They are also six times likelier to be more proud, 43 percent to 7 percent, and twice as likely to be more interested and hopeful. Right now, 44 percent of whites and just 11 percent of blacks say the election frustrates them, and whites are far likelier to say they feel angry and helpless.
-Liberals are three times likelier than conservatives to be more excited than they were and twice as likely to be more proud.
Nineteen percent of conservatives feel more helpless, compared to 9 percent of liberals.
-Overall, 44 percent of Obama voters have grown more interested in the campaign since the fall, compared to 35 percent of McCain's.
Currently, seven in 10 Obama backers say the campaign interests them, as do six in 10 of McCain's.
"It's exciting because it looks like we've got a winner," said Susan Gates, 55, a Democrat from Chelmsford, Mass.
All Democrats don't feel that way. Overall, 31 percent of those supporting Obama are Democrats who preferred Clinton during the party's prolonged primary battle this spring, and they are less enthused than those who have backed Obama longer.
Just 12 percent of former Clinton supporters say they are excited about the campaign, one-third the excitement level among Obama's longer-term backers. A fifth of them say the election makes them feel frustrated and helpless, and about as many say they may still change their minds, double the number of longtime Obama loyalists who say that.
"I was really hoping Hillary would pull it off," said Doreen Malinoski, 42, of Montclair, Calif., a Democrat who said she is uneasy with Obama's calls for change. "I mean, this is the best we can come up with?"
Independents, whom both McCain and Obama are avidly pursuing, remain underwhelmed. Only 21 percent find the election interesting - down from 31 percent in November - and just 7 percent say it's exciting. Substantial numbers say they feel frustrated, helpless and even bored.
Independents are about evenly divided between the two candidates, with about a quarter behind each. Four in 10 remain undecided, and half say they could still change their minds.
"I really don't like some of McCain's policies, yet I don't know that much about Obama," said Philip Doenges, 46, an independent from Indianapolis. "I'd kind of like someone who hasn't been in Washington."
The AP-Yahoo News poll of 1,759 adults was conducted from June 13-23 and has an overall margin of sampling error of plus or minus 2.3 percentage points. Included were interviews with 844 Democrats and 637 Republicans, for whom the margins of sampling error are plus or minus 3.4 points and 3.9 points, respectively.
The poll was conducted over the Internet by Knowledge Networks, which initially contacted people using traditional telephone polling methods and followed with online interviews. People chosen for the study who had no Internet access were given it for free.