The Republican zombie repeal and replace effort just died. Again.

(CNN)Maine Sen. Susan Collins' announcement Monday night that she would not vote for her party's last-ditch attempt to repeal and replace Obamacare doomed Republican hopes of abolishing a law they spent eight years campaigning against. Senate Republican leaders acknowledged that defeat Tuesday afternoon, deciding not to even bring the bill up for a vote on the floor.

What's remarkable about the failure of the legislation put forward by Sens. Lindsey Graham of South Carolina and Bill Cassidy of Louisiana, is not that it happened. It's how similar this failure was to the failure of Republicans' first attempt to repeal and replace the Affordable Care Act back in July. And how that intractability of the "no" votes proves one basic fact: There is no repeal and replace bill that can get 50 GOP votes in this Senate. Period.
In the wake of the July defeat, there was little expectation that a re-animation of the repeal and replace effort was even possible. The reason was simple: The GOP Senate conference was caught betwixt and between -- stretched to breaking by hardliners on the right who demanded full repeal and nothing but full repeal and centrists concerned about the elimination of popular provisions like Medicaid expansion and the guaranteed coverage for people with pre-existing conditions.
Those differences -- coupled with the fact that Republicans only controlled 52 seats -- made the policy, and the math, look impossible.
    Then, suddenly, out of nowhere came Graham-Cassidy -- a last chance for Republicans desperate to make good on their oft-repeated campaign trail promise to their base. The legislation -- with its block granting of health care dollars to the states -- was touted as the conservative solution to the morass created by Obamacare's federal government control. Finally, a Republican solution Republicans could vote for!
    Except that, on closer examination, Graham-Cassidy wasn't the amazing legislative solution that Republicans so badly wanted it to be. It had the same problems the last bill -- nicknamed "skinny repeal" -- had. It was the same package, just wrapped in different paper.
    The first "no" came from Kentucky Sen. Rand Paul, who said he had promised his voters full repeal of Obamacare and this wasn't that. (Paul, of course, had found a way to vote for skinny repeal back in July.)
    The second "no" came from Arizona Sen. John McCain, whose famous/infamous thumbs-down "no" vote in late July had doomed skinny repeal by the narrowest of margins. McCain's issue then was the same as his issue now: The legislation did not move through the Senate in "regular order" -- meaning that it didn't go through a series of committee hearings, a mark-up where the legislation was edited and improved and then floor votes in which amendments to the bill -- offered by Republicans and Democrats -- could be considered.
    Then, on Monday night, came Collins' "no." Her issues, then as now, were the potential cuts to Medicaid and the lack of guarantees that people with pre-existing conditions would be covered -- and covered at an affordable rate.
    "Sweeping reforms to our health care system and to Medicaid can't be done well in a compressed time frame, especially when the actual bill is a moving target," Collins said when announcing her decision.
    This all comes as the last few grains of sand slip out of the hourglass for Republicans. Due to the arcana of Senate procedure, the GOP has only until the end of this month -- which comes on Saturday -- to pass the repeal and replace measure with a simple majority. After Saturday, 60 votes are needed -- and even the most optimistic Republican senator acknowledges that simply isn't a realistic possibility.
    Which means Republicans must now come face to face with this fact: They will renege -- at least for now -- on an eight-year promise to their political base. A promise that played a central role in not only delivering Republican majorities in the House and Senate but also pushing Republicans to historic gains at the gubernatorial and state legislative level. And helping Donald Trump ascend to the White House last fall.
    For the eight years when they were out of the White House, Republicans talked of little else other than how, once they seized all levers of power in the legislative and executive branches, they would quickly eradicate Obamacare and replace it with a state-focused, free market system.
    It was the one issue -- other than President Barack Obama himself -- that united Republicans. Time after time after time the Republican majority in the House voted to repeal the law -- symbolic votes, of course, because they knew the man sitting in the Oval Office had no intention of getting rid of a law that bore his name.
    But Trump's victory changed all that. Many congressional Republicans held their noses and voted for Trump -- despite their misgivings about his tone and personality -- solely because of their belief that he was the final puzzle piece in their near-decade long quest to expunge the stain of Obamacare.
    Trump promised time and again on the campaign trail that his election would mean the end of the ACA -- and fast. At a rally in Pennsylvania exactly one week before the election, Trump said this:
    "When we win on November 8 and elect a Republican Congress, we will be able to immediately repeal and replace Obamacare. Have to do it. I will ask Congress to convene a special session so we can repeal and replace, and it will be such an honor for me, for you, and for everybody in this country because Obamacare has to be replaced and we will do it and we will do it very, very quickly."
    It didn't happen quickly and, at least with the current composition of Senate Republicans, it won't be happening at all.
    What Republicans have (re)learned over these past eight months of failure on health care reform is a lesson as old as politics: Campaigning is easy, governing is hard. Selling people on being against something is easy, selling people on being for something is hard.
    The conservative dream to repeal and replace Obamacare is dead for now. The question now is where Republicans go from here -- a bipartisan bill to fix what ails the ACA? -- and how their base, who had waited so patiently for so long, reacts to this failure.