WASHINGTON Congressional Democrats cautiously embraced President Barack Obama's new health care plan as their last hope for enacting a comprehensive overhaul. Republicans trashed it, dimming prospects for any deal at the bipartisan health care summit that Obama has scheduled for Thursday to try to jump-start the debate.

A year after calling on Congress to act to reform the nation's costly and inefficient health care system, Obama finally produced a plan of his own Monday. It used legislation already passed by the Senate as its starting point, making changes designed to appeal to House Democrats.

Even after months in which health care gradually turned from Obama's top domestic priority into a political albatross, Obama opted for one last attempt at full-scale legislation. It costs around $1 trillion over a decade, requires nearly everyone to be insured or pay a fine, and puts new requirements on insurance companies, including - in a new twist responding to recent rate hikes - giving the federal government authority to block big premium increases.

In the end Obama may have to settle for much less than what he proposed Monday - or nothing at all. But many Democrats said that despite all the bad-news polls and the loss of their filibuster-proof Senate supermajority in a special-election upset, it would still be better to pass a sweeping bill than make small changes or none at all.

If Obama fails on a comprehensive health care overhaul where Bill Clinton and other presidents failed before him, the chance won't come around again anytime soon.

"This is the last time out," said House Ways and Means Committee Chairman Charles Rangel, D-N.Y. "So this is it. This is it."

The whole endeavor will now rise or fall on Obama's ability to sell his plan at the summit Thursday, and the reaction from lawmakers and the public in the days ahead. Congressional Democrats got their first look at the proposal Monday morning. Reflecting the uncertain future of the health overhaul effort, many focused as much on the fact that Obama finally stepped in with a detailed plan of his own as on the policy details.

"The president needs to say 'This is what I'm for', and it sounds like he's done that," said Sen. Tom Carper, D-Del.

Obama's plan does not include the government insurance option sought by liberals and it dramatically scales back a tax on high-value insurance plans from the Senate bill that was opposed in the House. It eliminates a controversial Medicaid deal for Nebraska, offers all states more help with Medicaid funding, and beefs up subsidies to help lower-income people buy care, all changes that won praise from House Democrats. It also closes the so-called "doughnut hole" in Medicare's prescription drug coverage.

Individuals and small businesses would shop for insurance in regulated state-based marketplaces called exchanges.

Obama tried to avoid the mistakes Clinton made in delivering a health care proposal to Capitol Hill and telling Congress to pass it, but many now believe he erred in the opposite direction.

Republican leaders made no secret of their contempt.

"Democrats in Washington either aren't listening, or are completely ignoring what Americans across the country have been saying," said Senate Minority Leader Mitch McConnell, R-Ky. "Our constituents don't want yet another partisan, back-room bill that slashes Medicare for our seniors, raises a half-trillion dollars in new taxes, fines them if they don't buy the right insurance and further expands the role of government."

Rep. Eric Cantor, the House Republican whip, assailed the proposal Tuesday as a "repackaged" version of Senate-passed legislation that the American people already have rejected.

Cantor, R-Va., said "the American people do not like the Senate health care bill," and he suggested that Obama will be able to rely only on Democrats to push the bill through to final congressional passage. He called it a "nonstarter" and said the health care summit Obama has scheduled later this week likely won't be productive.

If Obama can't achieve agreement with Republicans, White House officials made clear Monday they're prepared to attempt to push the legislation through the Senate under controversial rules allowing a simple majority vote rather than the 60-vote supermajority Democrats no longer control.

"The president expects and believes the American people deserve an up or down vote on health reform," said White House Communications Director Dan Pfeiffer. "And our proposal is designed to give ourselves maximum flexibility to ensure that we can get an up or down vote if the opposition decides that they need the extraordinary step of filibustering health reform."

Under that approach, the House would have to pass the bill already passed by the Senate, and both chambers would then pass the package of changes released Monday by Obama. But it's not at all clear that Democratic leaders command the votes they need to pull it off in either chamber. If Obama chooses to go that route he'll have to work hard to bring balky Democrats along with him.

Cantor made his remarks on ABC's "Good Morning America."