A series of last-minute flare-ups ahead of a Sunday showdown vote on historic health care legislation threatened to slow the Democrats' march to passage, after more than a year of grueling effort and a turbulent debate that has left the country deeply divided.

The most intense focus among lawmakers was on a small group of Democrats concerned that abortion funding restrictions in the legislation do not go far enough. Determined to avoid votes on such a charged issue, Democratic leaders raised the possibility of an executive order from Obama that reaffirms existing federal law barring taxpayer-funded abortions except in cases of rape, incest or to save the life of the mother.

House Speaker Nancy Pelosi said Saturday she would not cut a deal to include tighter restrictions on abortion funding in the final health care bill, suggesting that she believes she has enough votes to pass the legislation without them. 

Pelosi told Fox News that there will be no vote on a separate bill adding abortion restrictions championed by Rep. Bart Stupak, D-Mich. to the final legislation. 

A spokeswoman for Stupak added, "discussions are continuing."

"I know this is a tough vote," the president told House Democrats at a meeting on Capitol Hill. "It will end up being the smart thing to do politically," Obama said.

"It is in your hands," Obama said, bringing lawmakers to their feet. "It is time to pass health care reform for America and I am confident that you are going to do it tomorrow."

Democratic leaders appeared confident they had the votes needed to pass the landmark legislation Sunday after frenetically hunting for votes inside the Capitol as angry protesters gathered outside with some hurling racial insults at black members of Congress.

Obama can rely only on Democrats to gain passage of his top domestic priority in a make-or-break vote for his presidency. He faces unanimous opposition from Republicans, who say the plan amounts to a government takeover of health care that will lead to higher deficits and taxes.

The Associated Press contributed to this report