WASHINGTON (AP) — Senate Republicans are revving up a final push to scuttle President Barack Obama's health care law. Though the effort faces low odds of success and just a two-week window to prevail, Democrats backed by doctors, hospitals, and patients' groups are mustering an all-out effort to smother the GOP drive once and for all.

The latest attempt is being led by GOP Sens. Lindsey Graham of South Carolina and Louisiana's Bill Cassidy. Their 141-page bill would replace much of Obama's statute with block grants to states and would give them wide leeway to decide how to spend the money. It would also end Obama's requirement that most Americans buy insurance and that companies offer coverage to workers.

A victory would let President Donald Trump and Senate leaders claim redemption on one of their top priorities, nearly two months after the chamber rejected earlier "repeal and replace" legislation and dealt a painful blow to the GOP.

After that embarrassing setback, Senate Majority Leader Mitch McConnell, R-Ky., said he'd not revisit the issue unless he was assured he had the votes he needed to succeed. He and other Republicans began refocusing on another big priority, a tax overhaul.

The sponsors say their proposal would let states decide what health care programs work best for their residents. Opponents say the plan's cuts in Medicaid and easing of Obama's insurance requirements would cause millions to become uninsured and leave others with skimpy, unaffordable coverage.

The earlier Republican effort crashed in July when the GOP-led Senate defeated three proposals for scrapping Obama's 2010 overhaul.

Cassidy and Graham have asserted they're close to rounding up the 50 Senate votes they'd need to win. Vice President Mike Pence would cast the tie-breaking vote.

But as it was in July, getting 50 votes from the chamber Republicans control 52-48 will be difficult.

Conservative Sen. Rand Paul, R-Ky., has already said he'll oppose the bill. Other Republicans who've not yet lined up behind it include Alaska's Lisa Murkowski, Susan Collins of Maine, Shelley Moore Capito of West Virginia and Ohio's Rob Portman.

Collins, Murkowski and McCain voted against the last measure Republicans tried pushing through the Senate in July, which failed 51-49.

Republicans only have until Sept. 30 to succeed with just 50 votes. Special procedures preventing Democrats from using a filibuster to kill the measure will expire after that, and Republicans would need 60 votes to win.

That's a number they won't reach because Democrats unanimously oppose the GOP effort.

Complicating their prospects, Republicans are waiting for an analysis by the nonpartisan Congressional Budget Office, which is needed before the Senate can vote.

The budget agency's evaluations of past GOP repeal plans concluded they would have caused millions of Americans to lose insurance coverage, an outcome many Republicans are unwilling to accept.

Top Democrats including Senate Minority Leader Chuck Schumer, D-N.Y., and House Minority Leader Nancy Pelosi, D-Calif., wrote to the budget office Monday asking that its analysis be "comprehensive," including showing the number of people that would lose coverage and the plan's impact on premiums.