Updated 11 p.m. ET

After seven years of promising to repeal the Affordable Care Act, Republican efforts at passing a health care bill on their own may have ended Monday night as the bill working its way through the Senate was effectively blocked. Two more GOP senators – Mike Lee of Utah and Jerry Moran of Kansas – came out in opposition to the bill, which means it cannot get enough support to pass.

Shortly afterward, President Trump wrote, "Republicans should just REPEAL failing ObamaCare now & work on a new Healthcare Plan that will start from a clean slate. Dems will join in!"

Senate Majority Leader Mitch McConnell put out a statement promising to do just that, pointing to a 2015 bill passed by Congress and vetoed by President Obama. It would repeal the ACA with a two-year delay, giving a fixed deadline for Congress to replace the law. McConnell would still need 50 votes to bring that to the floor and it's not clear he would have those votes.

McConnell has previously said turning to Democrats to come up with fixes for the current health care system is his next step, and several senators who criticized the crafting of the current bill in private have called for such a bipartisan process.

One such senator is John McCain, R-Ariz., who was kept from returning to Washington this week due to unexpected surgery for a blood clot, requiring GOP leaders to delay their push for the overhaul bill. In a statement late Monday, McCain said, "The Congress must now return to regular order, hold hearings, receive input from members of both parties, and heed the recommendations of our nation's governors so that we can produce a bill that finally provides Americans with access to quality and affordable health care."

McCain has been among the more moderate Republicans who have joined several GOP governors in opposing the Republican health care bill's proposed cuts to Medicaid. The bill would have represented a generational restructuring of the entitlement program. The Congressional Budget Office has not yet given its estimates on the impact of the latest Senate bill, but estimates on an earlier version showed the reductions in Medicaid coverage would have meant 15 million fewer Americans would have coverage under the program in 10 years.

In addition to paralyzing the GOP on its top political pledge for the better part of a decade, stalling on the health care bill could tie up the rest of the party's agenda, including efforts at major tax reform. The health care bill has dominated work on Capitol Hill for the first six months of Trump's term, typically the most potent period for an administration to move legislation, which is also the first period in a decade when the GOP has controlled both chambers of Congress and the White House.

Before Lee and Moran, Sens. Rand Paul of Kentucky and Susan Collins of Maine had announced their opposition. With those four voting no, only 48 other Republicans in the Senate, and no support from Democrats or independents, the measure was effectively dead.

"We must now start fresh with an open legislative process to develop innovative solutions that provide greater personal choice, protections for pre-existing conditions, increased access and lower overall costs for Kansans," Moran said in a statement.

As NPR's Geoff Bennett and Tamara Keith reported earlier this week, Senate Republicans, realizing how close the tally was, had delayed taking up the measure until McCain was well enough to return to the Senate.

Geoff and Tamara wrote: "McConnell had been in a rush to get the bill to a vote, in part because it was thought more time wouldn't help and could hurt the chance for passage."

New York Sen. Charles Schumer said in a statement that the "second failure of Trumpcare is proof positive" that the bill is "unworkable."

"Rather than repeating the same failed, partisan process yet again, Republicans should start from scratch and work with Democrats on a bill that lowers premiums, provides long term stability to the markets and improves our health care system," Schumer said.

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