(AP) - Republican Sen. John McCain has erased Sen. Barack Obama's 10-point advantage in a head-to-head matchup, leaving him essentially tied with both Democratic candidates in an Associated Press-Ipsos national poll released Thursday.
The survey showed the extended Democratic primary campaign creating divisions among supporters of Obama and rival Sen. Hillary Rodham Clinton and suggests a tight race for the presidency in November no matter which Democrat becomes the nominee.
McCain is benefiting from a bounce since he clinched the GOP nomination a month ago. The four-term Arizona senator has moved up in matchups with each of the Democratic candidates, particularly Obama.
An AP-Ipsos poll taken in late February had Obama leading McCain 51-41 percent. The current survey, conducted April 7-9, had them at 45 percent each. McCain leads Obama among men, whites, Southerners, married women and independents.
Clinton led McCain, 48-43 percent, in February. The latest survey showed the New York senator with 48 percent support to McCain's 45 percent. Factoring in the poll's margin of error of 3.1 percentage points, Clinton and McCain are statistically tied.
The last month has been challenging for Obama. The Illinois senator suffered high-profile losses in the Texas and Ohio primaries that encouraged Clinton, who pushed on even harder against him. Obama's campaign also suffered a blow with scrutiny of incendiary sermons delivered by his longtime pastor. The candidate responded by delivering perhaps the biggest speech of his campaign to call for racial understanding.
Obama is also facing almost daily critiques from Clinton and McCain, questioning whether the freshman lawmaker has the experience to be a wartime leader.
Despite all the conflict surrounding Obama, the Democratic contest is unchanged from February with Obama at 46 percent and Clinton at 43 percent. But the heated primary is creating divisions among the electorate - many Clinton and Obama supporters say they would rather vote for McCain if their chosen Democrat doesn't win the nomination.
About a quarter of Obama supporters say they'll vote for McCain if Clinton is the Democratic nominee. About a third of Clinton supporters say they would vote for McCain if it's Obama.
Against McCain, Obama lost ground among women - from 57 percent in February to 47 percent in April. Obama dropped 12 points among women under 45, 14 points among suburban women and 15 points among married women.
He also lost nine points or more among voters under 35, high-income households, whites, Catholics, independents, Southerners, people living in the Northeast and those with a high school education or less.
Although the race between Clinton and Obama remained unchanged, there were a few shifts in whom voters are choosing:
The gender gap has mostly disappeared, with Clinton losing her advantage among women. In February, 51 percent of Democratic women supported Clinton while 38 percent were for Obama. Now they're statistically tied at 44 percent for Clinton, 42 percent for Obama. That is partially offset by a decline in male support for Obama, down 7 points to 50 percent, while Clinton gained 10 points among men. She is now at 42 percent.
Obama and Clinton are now statistically about even among households earning under $50,000. In late February, Clinton led 54 percent to 37 percent, but now it is just 48 percent to 41 percent.
Obama now leads Clinton among self-described moderate Democrats, 51 percent to 35 percent. Previously they were 45 percent Clinton, 40 percent Obama.
The poll questioned 1,005 adults nationally. Included were interviews with 489 Democratic voters and people leaning Democratic, with a margin of sampling error of plus or minus 4.4 points; and 369 Republicans or GOP-leaning voters, with a margin of sampling error of plus or minus 5.1 points.