If James Comey, the F.B.I. director, hadn’t tipped the scales in the campaign’s final days with that grotesquely misleading letter, right now an incoming Clinton administration would be celebrating some very good news. Because health reform, President Obama’s signature achievement, is stabilizing after a bumpy year.

This means that the huge gains achieved so far — tens of millions of newly insured Americans and dramatic reductions in the number of people skipping treatment or facing financial hardship because of cost — look as if they’re here to stay.

Or they would be here to stay if the man who squeaked into power thanks to Mr. Comey and Vladimir Putin wasn’t determined to betray his supporters, and snatch away the health care they need.

To appreciate the good news about Obamacare you need to understand where the earlier bad news came from. Premiums on the exchanges, the insurance marketplaces created by the Affordable Care Act, did indeed rise sharply this year, because insurers were losing money. But this wasn’t because of a surge in overall medical costs, which have risen much more slowly since the act was passed than they did before. It reflected, instead, the mix of people signing up — fewer healthy, low-cost people than expected, more people with chronic health issues.