Affluent young people might end up saving some money as a result of these changes. But the effect on those who are older and less affluent would be devastating. AARP has done the math: a 55-year-old making $25,000 a year would end up paying $3,600 a year more for coverage; that rises to $8,400 for a 64-year-old making $15,000 a year. And that’s before the death spiral.

For the combination of price hikes and weakened penalties would lead many healthy Americans to forgo insurance. This would worsen the risk pool, causing premiums to rise sharply — and remember, subsidies would no longer adjust to offset this rise. The result would be even more people dropping out. Republicans have been claiming that Obamacare is collapsing, which isn’t true. But Trumpcare, if implemented, would collapse in a Mar-a-Lago minute.

How could House Republicans under the leadership of Paul Ryan, who the media keeps assuring us is a smart, serious policy wonk, have produced such a monstrosity? Two reasons.

First, the G.O.P.’s policy-making and policy analysis capacity has been downgraded to the point of worthlessness. There are real conservative policy experts, but the party doesn’t want them, perhaps because their very competence makes them ideologically unreliable — a proposition illustrated by the rush to enact this bill before the nonpartisan Congressional Budget Office can estimate either its costs or its effects. Basically, facts and serious analysis are the modern right’s enemies; policy is left to hacks who can’t get even the simplest things right.

Second, Republicans seem to have been undone by their reverse-Robin-Hood urges. You can’t make something like Obamacare work without giving lower-income families enough support that insurance becomes affordable. But the modern G.O.P. always wants to comfort the comfortable and afflict the afflicted; so the bill ends up throwing away the taxes on the rich that help pay for subsidies, and redirects the subsidies themselves away from those who need them to those who don’t.

Given the sick joke of a health plan, you might ask what happened to all those proclamations that Obamacare was a terrible, no good system that Republicans would immediately replace with something far better — not to mention Donald Trump’s promises of “insurance for everybody” and “great health care.”

But the answer, of course, is that they were all lying, all along — and they still are. On this, at least, Republican unity remains impressively intact.