The campaign to let 20 million Americans keep their health insurance is working.

It still has a long way to go, and it’s not guaranteed to succeed. But the progress of the last couple months is remarkable.

Thanks in part to a surge of activism — town hall meetings, online postings, calls to Congress — the politics of Obamacare have flipped. Many Americans have come to realize that the care part of the law matters much more than the Obama part. As a result, the Republicans no longer have a clear path to repeal.

President Trump, in his speech to Congress on Tuesday night, will probably pretend otherwise. He may repeat the same magical promises to pass a bill that’s better and cheaper and covers everyone. Privately, though, he and his aides have begun to realize the mess they have made by promising the impossible.

On Monday, Trump himself lamented that health care was “complicated.” The clearest sign of anxiety came in a Washington Post report: Four top advisers — Stephen Bannon, Gary Cohn, Jared Kushner and Stephen Miller — “have emphasized the potential political costs to moving aggressively.” Those costs include taking the blame (fairly or not) for every problem in the insurance market.