In his speech, the president told the cheering crowd "the time is now" for healthcare reform.
He said he "didn't want to give everything away" ahead of a prime-time speech he will give Wednesday to a joint session of Congress. But he added: "It's time to do what's right for America's working families, to put aside the partisanship, to come together as a nation, to pass health insurance reform now, this year."
Listen to the full speech:
The president's Wednesday speech will come as Congress returns to work this week after its August recess. White House officials have told news organizations that the speech will make clear the president's stance on specific elements of a health care reform bill.
"People will leave [Wednesday's] speech knowing where he stands," White House press secretary Robert Gibbs said Sunday on ABC's "This Week," according to the New York Times. Gibbs said that the president is not likely to threaten to veto specific bill options, but added that "I'm sure he will draw some lines in the sand."
Until now, Mr. Obama has been reluctant to take firm positions on some of the most controversial aspects of health care reform, including a government-run public plan option. Instead he's preferred to let Congress work out the details of a plan.
That's in contrast to President Bill Clinton's 1993 approach to health care reform, in which the administration sent a fully-developed health care bill to Congress that, in the end, failed to attract much support from either party and stalled out on Capitol Hill.
Watch experts discuss the 1993 reform effort here.
But President Obama's approach has stirred problems as well, with months of contentious debate in Congress and in lawmakers' home districts. As of yet, no compromise bills acceptable to both parties have surfaced.
Only one Congressional committee is still negotiating a bipartisan bill. The Senate Finance Committee has a Sept. 15 deadline to produce a compromise bill.
Now, both supporters and critics of the president say, he must seize control of the debate and take the political risk of supporting specific proposals.
"It goes without saying that a lot is riding now on [President Obama's] ability to re-energize the health care debate and bring it home to a successful conclusion," John Podesta, who ran the president's transition team and advises him on health care, energy and other issues, told the New York Times.
The president is walking a fine line on issues like the public option. He has said that he would prefer a public plan option that would provide competition to private insurers, but has added that he would not make it a condition of signing a bill. Nearly all Republicans oppose the idea, and no bill with a public plan option has attracted any Republican votes in any committee. However, some more liberal Democrats in the House say that they will not vote for a plan that does not include a public option.
The Senate Finance Committee is reported to be considering a bill that would create private, non-profit health insurance cooperatives instead. And one moderate Republican, Sen. Olympia Snow of Maine, has raised the idea of creating a bill with a "trigger" provision that would create a public option at some later time only if private insurers failed to come up with affordable, acceptable plans in a specified amount of time.
White House officials have said in private conversations that they are prepared to scale back their plans for health care legislation, according to the New York Times, perhaps even accepting a pared-down bill that could serve as a basis for future reform.
---- Compiled from wire reports and other media sources