The concerted conservative opposition was a remarkable rebuke to legislation GOP leaders hope will fulfill seven years of promises to repeal and replace Barack Obama's Affordable Care Act, pledges that played out in countless Republican campaigns for House and Senate as well as last year's race for president. Instead, the groups that are uniting to oppose the new House legislation include many that sprang up to oppose passage of "Obamacare" in the first place.

"As the bill stands today, it is Obamacare 2.0," the billionaire Koch Brothers-backed Americans for Prosperity and Freedom Partners Chamber of Commerce said in a statement. "Millions of Americans would never see the improvements in care they were promised, just as Obamacare failed to deliver on its promises."Republicans are pushing forward even without official estimates from the Congressional Budget Office on the cost of the bill and how many people would be covered, although GOP lawmakers acknowledge they can't hope to match the 20 million covered under Obamacare.

Democrats say the bill would leave many people uninsured, shifting costs to states and hospital systems that act as providers of last resort. The bill also adds up to big tax breaks for the rich, cutting more than 20 taxes enacted under Obama's heath law, with the bulk of the savings going to the wealthiest Americans.

"This is a tax cut for the wealthy with some health insurance provisions tacked alongside of it," said Senate Minority Leader Chuck Schumer, D-N.Y.

Many conservatives are hardly happier.

The new legislation is "not the Obamacare replacement plan, not the Obamacare repeal plan we've been hoping for. This is instead a step in the wrong direction," Sen. Mike Lee, R-Utah, said at an afternoon news conference with Rand Paul and members of the House Freedom Caucus.

Caucus members command enough votes to take down the bill in the House, but the group's chairman, Rep. Mark Meadows of North Carolina, struck a conciliatory tone, emphasizing they are open to negotiation and view the leadership bill as a starting point.

Notes of caution also came from GOP governors, with Ohio Gov. John Kasich arguing that phasing out expanded Medicaid coverage without a viable alternative is "counterproductive" and Illinois Gov. Bruce Rauner saying he was "very concerned" that people will be "left in the lurch" under the House GOP plan.

Committee votes on the new bill are to begin Wednesday in the House, and GOP leaders hope to push it through the Senate soon thereafter.

Even as some Republicans expressed doubts about whether that would be possible, Speaker Ryan said at an afternoon news conference, "We'll have 218 when this thing comes to the floor, I can guarantee you that." That's the number of votes needed for passage.

AP