Those of us who preferred a single-player health care law, like Medicare, and who were chagrined at the flaws in Obamacare, including the lack of a public option, must now recognize, as we work toward improving Obamacare over time, that for all its imperfections, it provides benefits that are crucial to millions of people who didn’t have those benefits before Obamacare, and who didn’t know how precious those benefits were to them, until they had them. And until Republicans, whom many of them had voted for, threatened to take those benefits away.

Obamacare was imperfect progress, but that is almost always how progress is made. And the inertia of imperfect progress is difficult to overcome, and explains why seven years later the Republican efforts to do so were doomed.

The Republican position on health care, from the start, before Obamacare was passed, was to have NO health care legislation. Therefore, their goal was to defeat Obamacare when it was proposed, as they had the earlier Clinton proposal at the end of the 20th century, and remain at the status quo, with tens of millions of people uncovered by insurance and, therefore, without access to health care.

But they weren’t able to defeat Obamacare, and thus, their efforts over the past seven years to repeal it, to go back to a time before it passed, to return to the situation that would have existed had they defeated Obamacare, as they had the earlier Clinton bill, became more and more quixotic the longer Obamacare existed.

As more and more people, many of whom had opposed Obamacare, began to benefit from it, it became harder and harder to take those benefits away, harder and harder to go back to the time before Obamacare. As a result, the Republican campaign to repeal Obamacare, necessarily became, had to become, repeal and replace.

This was because of an insufficiently recognized political reality: the inertia of partial progress. This reality was perhaps best exemplified by the old Robert Moses “get the legislature to authorize the first ten miles of a proposed 100-mile road, and it will be very difficult, and as a practical matter probably impossible, for them subsequently to refuse to authorize the remaining 90 miles, once the first 10 miles are built.”

That reality was also why, once Social Security was enacted, with all its omissions and imperfections, it has proved impossible to do away with, and it has been expanded instead. This is because once lots of people receive benefits, they come to believe they are entitled to them, they get used to and dependent upon them, they see them as normal and as theirs by right, and even though they might not have clamored for such benefits before they were enacted, once they are enacted and people get used to them, they cannot politically be taken away, at least not easily. This is particularly true of benefits that inure to an electorally potent constituency.

That may be the mistake made in 1969-1970 by liberal opponents of President Nixon’s proposed negative income tax, designed as an entitlement to replace discretionary welfare payments. Although the politics were complicated at the time, and constantly shifting, at least some of the liberal opposition was based on the ground that the dollar amounts of the proposed negative tax payments were insufficient. They were insufficient, but once enacted, and written into the tax code, they would have probably become less politically vulnerable than discretionary welfare payments, and the amounts would probably have increased over time.

That’s also why it’s hard, if not impossible, to eliminate mortgage interest and real-estate tax deductions for homeowners, despite the fact that it is a subsidy not provided to renters, even though renters pay a portion of their landlords’ mortgage interest payments and real-estate taxes that is factored into their rents.

Benefits that are difficult, or nearly impossible, to initiate are even more difficult, if not impossible, to take away once people have them. That is why it is politically critical to initiate benefits, even if imperfectly or flawed.

Thus, once the Republicans failed to defeat Obamacare legislatively, or to block it judicially, and many millions of people previously uncovered began to benefit from it, and to rely on such benefits, once such benefits became normalized and part of people’s calculus of expectations, the G.O.P. strategy of returning to a time prior to Obamacare became impossible.

Now the Republicans stood on different ground. The strategy of Repeal had to be changed to a strategy of Repeal and Replace. Now, if they wanted to get rid of Obamacare, they would have to do something they never had to do before and never wanted to do: propose something better.

But as long as the Republicans were powerless to actually do anything about Obamacare except fume and fulminate and rile up their constituencies, they never had to confront the REPLACE part. That is, without control of both houses of Congress and the presidency, the distinction between “repeal” and “repeal and replace” was academic, and politically inconsequential. As long as they were powerless to defeat Obamacare, a singular strategy of REPEAL, which only required them to say NO over and over again, to pass more than 60 bills, all of them futile, repealing Obamacare, without ever having to offer an alternative to replace it, had only positive political consequences (rallying their troops with the delusion that they could return to a pre-Obamacare time) and no negative consequence, because they had no need to propose an alternative.

In the pre-Obamacare time, no alternative was necessary, because the Republican position was that no healthcare legislation was necessary, and because no one had yet had any benefits from such legislation, there was no substantial pushback politically. NO was enough; YES to something else wasn’t yet politically required. And so the G.O.P. remained united.

But once they gained control of both houses of Congress and the presidency, Republicans were confronted by the distinction. Now, they couldn’t just repeal, because now repeal by itself would strip too many people, including, critically, many of their own constituents, of benefits upon which they had come to rely.

Some of those people weren’t even aware that “Obamacare,” which they opposed, was the same thing as the Afforfable Care Act, which was the source of their benefits; like the voter who screamed “Keep the government away from my Medicare!”, they had no idea about the source of their benefits; but they would surely know if those benefits were taken away, and they wouldn’t like it.

So now, once Republicans had the power, NO wasn’t enough; there had to be a YES as well. REPEAL wasn’t enough; now REPEAL AND REPLACE was politically required. The Republicans wished to go back to the time before Obamacare, but that was no longer politically feasible, for now they stood on the ground established by seven years of Obamacare, a ground not where people wouldn’t clamor for benefits they could not imagine, but rather a ground where benefits, however inperfect, already existed, and where people would be furious and politically punitive if those benefits were taken away. The inertia of Obamacare had altered the politics of opposing it.

Thus the Republicans now had to do something they had never done before, never needed to do before, and didn’t believe in doing: they had to come up with an affirmative plan to provide health care coverage for at least everyone that was now covered by Obamacare. That is why REPEAL had to become REPEAL AND REPLACE. NO had to be accompanied by some sort of YES. And both doctrinally and politically, they were utterly unprepared for this, in part because they never expected to have the political power of both Houses and the presidency anytime soon.

So the demagogic, scorched earth oppositional anti-Obama strategy, which had worked to rally their electoral constituency even against its own interests, and helped vault them into power, now suddenly was transformed into the need to govern, to stand upon ground they wished to avoid and to actually do something that before Obamacare only Democrats would do: propose an affordable plan to provide health care coverage for people who before Obamacare did not have it. Now they had to come up with some sort of YES.

That they were utterly unable to do so is now evident. And even if they had managed to stitch something together, they would have been electorally punished for it.

The truth is the Republicans gained power by refusing to govern, but they cannot govern that way.

The only question now is how much damage can they do, not only to those who didn’t vote for them, but to those who did.

And how long will it be and how much damage will it take before the sufficiency of their electoral support disappears?