WASHINGTON (AP) — Barack Obama has won over more than half of Hillary Rodham Clinton's former supporters, according to an Associated Press-Yahoo News poll that finds party loyalty trumping hard feelings less than three weeks after their bruising Democratic presidential contest ended.

The poll suggests time is beginning to heal some rifts from the primary campaign and that the New York senator's endorsement of Obama carried weight. The poll was taken in the days after Clinton suspended her campaign and said she was supporting her rival.

Obama's progress with Clinton supporters is marked, yet far from complete. More than one in five who had backed the New York senator now plan to support Republican John McCain in the fall, a boost for McCain if those opinions hold.

"We still have work to do," Obama campaign manager David Plouffe told reporters in a strategy briefing.

Obama announced Thursday that he will help pay off Clinton's more than $20 million debt, personally writing a check in a gesture meant to win over her top financial backers.

Obama met with more than 200 of Clinton's biggest fundraisers at Washington's Mayflower Hotel, the first step in a two-day push to bring her supporters onboard this general election campaign. Behind the scenes, the two sides were negotiating her future involvement with the campaign.

Some Clinton donors had been frustrated that the Democratic presidential nominee-in-waiting had not done more to help her pay the bills even as they are expected to help fund his campaign.

Obama received a standing ovation from the crowd of more than 200 when he said he would enlist his supporters to help pay off her debt.