Prospects are good for resolving a dispute over abortion that has led some House Democrats to threaten to withhold support of President Obama's health-care overhaul, a key Michigan Democrat said Monday.

TAWAS CITY, Mich. — Prospects are good for resolving a dispute over abortion that has led some House Democrats to threaten to withhold support of President Obama’s health-care overhaul, a key Michigan Democrat said Monday.

Rep. Bart Stupak said he expects to resume talks with House leaders this week in a quest for wording that would impose no new limits on abortion rights but also would not allow use of federal money for the procedure.

“I’m more optimistic than I was a week ago,” Stupak said between meetings with constituents in his northern Michigan district. “The president says he doesn’t want to expand or restrict current law (on abortion). Neither do I.”

Stupak has emerged as spokesman for about a dozen House Democrats who supported health legislation approved by the House in November but contend a $1 trillion version that passed the Senate would authorize federal abortion subsidies. They insist on restoring stiffer restrictions Stupak added to the House measure.

Stupak had said last week that nothing had changed and he didn’t think the House leaders had the votes to pass the bill.

Meanwhile, in a high-octane appearance in suburban Pennsylvania that hearkened back to his “yes we can” campaign days, President Obama took direct aim at those who have warned the health push could cost the Democrats their majority in the November elections.

Appearing before 1,800 students and others at Arcadia University, outside of Philadelphia, Obama made an emotional pitch for public support as he tries to push the legislation through a final series of votes in the next several weeks.

“They’ve warned us we may not win,” Obama said of his doubters and critics. “They’ve argued now is not the time for reform. It’s going to hurt your poll numbers. How is it going to affect Democrats in November? Don’t do it now.

“My question to them is: When is the right time? If not now, when. If not us, who?”

Citing big rate increases for individual insurance policies in some states — 40, 60, even 100 percent — Obama sought to focus attention on provisions in the legislation that he said would protect consumers from the worst excesses of insurers, give people more choice among insurance policies, insure most people who do not have coverage and put downward pressure on costs.

He alluded to letters he has received from cancer survivors and others who have been priced out of the health-care market.

“What should I tell these Americans?” Obama said. “That Washington’s not sure how it will play in November? That we should walk away from this fight?”

Obama’s trip came as Democratic congressional leaders raced to resolve the remaining differences between the House and Senate versions of the legislation and to draft formal language that would allow for a new cost estimate by the Congressional Budget Office.

On Wednesday, Obama is to travel to St. Louis for another campaign-style rally for health care, White House officials said. On Tuesday, the group Health Care for America Now plans a march in Washington to support a package.

Meanwhile, New York Rep. Eric Massa, a Democrat, is blaming his resignation on a conspiracy by House Democratic leaders to force him out before a crucial vote on health care, his third explanation for leaving office after he cited health issues and an ethics investigation.

One of 39 Democrats who voted against an earlier House version of the health-care bill, Massa said in his weekly radio address Sunday that Democratic leaders will “stop at nothing” to advance the overhaul.

Facing a harassment complaint from a male staffer, Massa said Friday he would step down. His resignation took effect Monday. Days earlier, he said he wouldn’t seek re-election due to health problems.

But Massa insisted politics was the broader reason that led to a move to force him from office. “I was set up for this from the very, very beginning,” he said.

Katie Grant, a spokeswoman for House Majority Leader Steny Hoyer, said Massa’s accusation is “completely false.”