WASHINGTON — Seven years of Republican promises to repeal and replace President Barack Obama's signature health law came crashing down Tuesday, the party unable to advance its latest attempt to deliver despite controlling the White House, the Senate, and the House of Representatives.

A Senate GOP bill to rewrite the law met too much internal resistance, and a fall-back option — repeal the Affordable Care Act now, come up with a replacement later — faced imminent demise in the face of deep Republican divisions and a narrow two-vote majority.

Nevertheless, Senate Majority Leader Mitch McConnell (R., Ky.) said he would hold a vote early next week to simply repeal the law, known as Obamacare, with a two-year delay in order to come up with a replacement that can pass. At least four of the 52 GOP senators have said they would oppose it, and every Democrat also is expected to vote against it.

Republicans appear likely to head home for the summer recess with no major legislative accomplishments to show for their newfound power in Washington, and they signaled that they were ready to move on to other matters.

President Trump, who promised an overhaul of the health system but has vacillated between strategies, said he was "very disappointed." He blamed Democrats, who uniformly opposed the Republican approach, though the GOP had adopted rules that would have allowed Republicans to pass the bill without a single vote from the other party.

"I think we're probably in that position where we'll just let Obamacare fail," the president said. "We're not going to own it. I'm not going to own it, I can tell you. The Republicans are not going to own it. We'll let Obamacare fail, and then the Democrats are going to come to us and they're going to say, 'How do we fix it?' "

On Capitol Hill, Republican leaders said they were ready to move to tax reform and infrastructure while planning hearings on health care that signal a much longer, slower process for revamping a law they have campaigned against for years.

"As of today we just simply do not have 50 members who can agree on what ought to replace the existing law," McConnell told reporters. "My suspicion is there'll be hearings about the crisis that we have, and we'll have to see what the way forward is."

While Republicans could still revive their effort on health care, this was their best chance yet after years of symbolic repeal votes, and the first major test of their governance. The failure could threaten future efforts, said Rep. Tom MacArthur (R., N.J.), who worked closely with the White House to muscle a repeal bill through the House.

"While it ratchets up pressure on us to get something done, it also makes it difficult to move forward with anything controversial because of a fear of it falling apart," he told reporters.

The collapse — which began with critical GOP defections Monday night as Trump dined with a handful of senators — came six months after Republicans assumed control of every elected branch of the federal government and weeks after an initial Senate bill fell apart for lack of support.

Republicans were torn by sharp differences between moderates and conservatives and by frustration from rank-and-file lawmakers who felt left out of the picture on a sweeping bill with massive implications.

Some said the bill would go too far and threatened health care in their states, while others said it needed to go even further to rip up Obamacare. One of the most vocal opponents, Sen. Susan Collins (R., Maine), complained that the bill would make major changes to a long-standing health program, Medicaid, without a single hearing.

"The Senate should take a step back and engage in a bipartisan process to address the failures of the ACA and stabilize the individual markets," said a statement from Sen. Lisa Murkowski of Alaska, one of the Republicans standing in the way of repealing the law without a ready replacement.

Democrats said they would be open to compromise bills that would improve the law. but only if Republicans dropped the idea of a sweeping repeal or undermining it by declining to enforce its key provisions.

"It has to be not only that they don't do the repeal, but they also don't continue with the sabotage," said Rep. Frank Pallone of New Jersey, the top Democrat on the House committee that oversees health policy.

Sen. Bob Casey (D., Pa.) said he could envision cooperation on individual bills to fix specific parts of the ACA, rather than overhauls.

"If they can get beyond that," he said, senators could begin "a different chapter where we can focus on the real problems. Let's talk about it, do something really radical — have hearings."

Gov. Wolf and 10 other governors — five Republicans, an independent, and four more Democrats — also signed a statement urging lawmakers to work with governors of both parties to stabilize health insurance markets.

The head of the Senate committee that oversees health policy, Sen. Lamar Alexander (R., Tenn.), announced plans for hearings on health insurance. Other Republicans, including Sen. John McCain of Arizona, called for a bipartisan bill that moves through the normal committee process.

On an issue this complex, that process would likely be a long slog.

Sen. Pat Toomey (R., Pa.), who helped write the Senate bill, warned of a missed opportunity.

"History will look back on this moment and harshly judge this Congress for not beginning the process of replacing Obamacare and for failing to put Medicaid on a sustainable trajectory when we had the opportunity to do so," he said in a news release.

But there were signs that the GOP was moving on to another of its top priorities: an overhaul of the tax code. Toomey, a leading Republican voice on fiscal policy, met with House Speaker Paul Ryan to discuss the issue, according to a senior House GOP aide.

Republicans had hoped passing the health-care bill, with deep spending cuts, would create savings that could be used in a tax overhaul. That prospect now appears lost, but tax changes are likely to have broader support within the party and might be more attractive to moderate Democrats.

"Inevitably we're going to have to keep working on health care because Obamacare is collapsing all around us, and the status quo is totally not acceptable," Toomey said as he left his meeting with Ryan. "But we also can't let it prevent us from functioning, so there has been work being done on tax reform."

That now appears to represent Republicans' next chance to score a big legislative achievement in Trump's first year.