Now you know why Barack Obama, Nancy Pelosi and Harry Reid were so desperate to pass Obamacare that they made all those promises they knew they couldn’t keep and insisted their colleagues pass the bill so we could find out what was in it.

Because what was in it was precisely the kind of intractable, middle-class entitlement the rest of us warned against, the kind of law Republicans can, as with reforms to welfare programs and other entitlements, tweak but not fully eradicate at once.

That much is clear from the plan House Republicans released Monday . It repeals large chunks of Obamacare and replaces them with provisions that are marginally to substantially more conservative. But their plan does not remove the law root and branch, as so many of them promised.

There is a reason Obama, Pelosi and Reid were willing to sacrifice so many Democratic seats in Congress to push the bill through. A reason they put health reform before climate change, immigration and so many other liberal priorities.

Obamacare, more than anything else they might have done with their filibuster-proof majority, was personal enough to enough Americans as to render it, once in place, both unpopular and immovable. If that seems like a contradiction, consider the bias many Americans have toward the status quo. That’s why public opinion of Obamacare has improved even as its biggest elements have been failing and as the likelihood of its repeal has increased: Lots of people prefer the devil they know.

That includes state governors. The offer of “free” federal money to expand Medicaid was so alluring that many GOP-led states went for it. They, too, are now constituents for the status quo.

All that, plus Democrats’ determination to protect Obamacare, puts Republicans in a poor position. There are not 60 votes to repeal and replace — anyone who spent the Obama era defending the filibuster cannot now ignore it — so the reconciliation process is the only route. And there are limits to what can be done that way, particularly when it comes to passing a replacement.

There are some folks on the right who would be content to repeal now and take more time to craft a replacement. Not only is it far from clear Congress could pull that off. It isn’t a good idea, either: The public’s bias toward the status quo also means lots of people won’t accept nothing in the interim, even if they previously opposed Obamacare.

What we are left with, then, is the first in (one hopes) a series of incremental changes. And incremental changes to a landmark law are bound to feel inadequate.

Oh, it might be possible to adjust the House GOP plan here and there. But the essence of what can be done today is already in it. If you doubt that, look no further than President Trump’s quick evolution from talking about negotiating with Congress to supporting it strongly.

That will make a lot of voters mad at Republican lawmakers. Those lawmakers deserve it, for repeatedly promising more than they could deliver.

But the hope now has to be that the GOP will keep chipping away at Washington’s market-distorting role in health care as these initial changes take root. If you find that disappointing after all these years, you’re not alone.