Even without a proper analysis, however, it’s clear that Trumpcare breaks every promise Republicans ever made about health. Deductibles will rise, not fall, as insurers are set free to offer lower-quality coverage. Premiums may fall for a handful of young, healthy, affluent people, but will rise and in many cases soar for those who are older (because age spreads will rise), sicker (because protection against discrimination based on medical history will be taken away), and poorer (because subsidies will go down).

Many people with pre-existing conditions will find insurance either completely unavailable or totally out of their financial reach.

And Medicaid will be cut back, with the damage worsening over time.

The really important thing, however, is not just to realize that Republicans are breaking their promises, but to realize that they are doing so with intent. This isn’t one of those cases where people try to do what they said they would, but fall short in the execution. This is an act of deliberate betrayal: Everything about Trumpcare is specifically designed to do exactly the opposite of what Trump, Paul Ryan and other Republicans said it would.

Which raises two questions: Why are they doing this, and why do they think they can get away with it?

Part of the answer to the first question is, presumably, simple greed. Tens of millions would lose access to health coverage, but — according to independent estimates of an earlier version of Trumpcare — people with incomes over $1 million would save an average of more than $50,000 a year.

And there is a powerful faction within the G.O.P. for whom cutting taxes on the rich is more or less the only thing that matters.

And on a more subjective note, don’t you get the impression that Donald Trump gets some positive pleasure out of taking people who make the mistake of trusting him for a ride?