It was a big gamble, one that mixed self-imposed deadlines, White House pressure, secret sessions and a fierce hunger for a Republican win. And it did not pay off Tuesday, as Senate Majority Leader Mitch McConnell announced the chamber would not meet its own goal of passing an Obamacare repeal bill before the July 4 congressional recess.

The effort is not dead, and lawmakers say they will continue to work to forge a bill that addresses concerns by members worried about everything from opioid addiction coverage to stabilizing individual insurance markets. But the failure to even get the votes to proceed on a Republican health care bill means GOP lawmakers will go back to their states and districts for the Independence Day holiday without having fulfilled a campaign promise they have been repeating for 7 years.

"It's a big, complicated subject," Senate Majority Leader Mitch McConnell told reporters after a Republican caucus lunch. Such bills "are hard to pull together and hard to pass," the Kentucky Republican said.

That has surely been the case every time Congress has tried to pass a sweeping health care law, including when former President Obama, who, like President Donald Trump, enjoyed an early advantage of having one-party control of the White House and both chambers of Congress, managed to get the Affordable Care Act passed in 2010. And, more recently, when the GOP House stumbled on its first effort, only to pull the bill, and then manage passage on a second try.

But McConnell, under pressure from a embattled White House eager for a "W" in the legislative record, tried to push the measure through too quickly, lawmakers in both parties say, and members balked.

"Why vote when we can wait a little longer?" says Sen. Tim Scott, R-S.C., noting "real questions" many of his colleagues had about the measure. McConnell had assigned a 13-man team to write the bill behind closed doors, and some of their colleagues groused that they were being asked to vote on something that affects nearly one-sixth of the U.S. economy without being able to review it thoroughly first.

Nor did McConnell put the bill through what is called "regular order," meaning committee hearings, expert witnesses and an amendments process. Instead, the leader had an ambitious agenda of holding a procedural vote Tuesday or Wednesday and voting on the full measure Thursday or Friday. House Republicans were even told to keep their schedules loose in case they needed to come in over the weekend to consider the Senate package.

The advantage of such a process is that it relies on momentum, spurred in this case by a deep GOP desire to both erase Obamacare and get a legislative win, and leaves little time for opponents to organize and badger lawmakers.

That approach did not work for McConnell. First, the bill was already unpopular; the somewhat-similar House version had just 17 percent support in public polls. Opponents who were already harassing House lawmakers at town hall meetings were mobilized to do the same to senators.

The momentum also was slowed by the release of a Congressional Budget Office Research Service report showing that 22 million people would lose their insurance if the Senate bill became law – 15 million of them next year. That was marginally better than what the CBO projected for the House version.

And finally, a small group of senators had substantive problems with the bill several said would keep them from voting in favor of the "motion to proceed," needed to get the bill up for an up-or-down vote. Four senators said the measure did not go far enough to undo Obamacare, while several others expressed concerns about deep cuts in Medicaid.

Medicaid is commonly thought of as a health care program for the poor, but it also covers people with disabilities (including children with special needs) as well as nearly two-thirds of nursing home patients. States with opioid addiction problems would also be hurt, as many of those in treatment are on Medicaid.

"The bill is rotten to the core," said Democratic Senate Leader Chuck Schumer, noting that the measure provides a tax break for wealthier Americans. He predicted it would not be improved to the point where it could pass. With a 52-48 party advantage, McConnell can only lose two GOP senators, with Vice President Mike Pence breaking a tie. "It's not going to change with any little tweak that wins over this senator or that," the New York lawmaker told reporters.

Sen. John Barrasso, a Wyoming Republican who is a member of the leadership team, says the need to fix "collapsing" Obamacare will help the party get to 50. "It's critical that we do this. We have to rescue the American people from the collapses we are seeing" in the Obamacare health care exchanges, Barrasso says.

But while House Speaker Paul Ryan was able to cobble together a majority for a health care bill despite concerns from both the moderates and the conservative Freedom Caucus wing of his party, the wily McConnell has a more daunting task ahead.

Several House Republicans have acknowledged that they were unhappy with the bill, but voted for it to move the process along, hoping to improve it during negotiations with the Senate. Senators would not have that option, especially if leaders decide to simply present a Senate-passed bill to the House for a final vote there.

And if the Senate were to approve its own bill, there's no guarantee it will be acceptable to enough House Republicans. If the Senate bill is modified, for example, to accommodate lawmakers unhappy with the Medicaid cuts, the measure could lose support among House Freedom Caucus members.

With so much uncertainty about the final outcome, senators may think twice about walking the plank for an unpopular bill that might not get signed into law anyway - but could be used against them in opponents' campaign ads. Once a "motion to proceed" is approved, Democratic senators will surely offer up amendments that would kill the bill if approved, but be politically difficult for Republican senators to vote against.

"What rational senator wouldn't want to escape a vote-a-rama, which is all about 'gotcha' votes, if the vote is going to go down?" says Sen. Mark Warner, D-Va. "And the upside is that the wealthiest get a tax cut? I don't know how anybody would defend that," Warner adds.

GOP senators say staff will work to address some of the issues reluctant lawmakers have, so proposals can be scored (assigned a financial impact) over the break. But they're not sure what the result will be.