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 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."

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.