On Saturday pretty much the entire medical sector — groups representing doctors, hospitals, and insurers — released an extraordinary open letter condemning the Graham-Cassidy health bill. The letter was written in the style of Emile Zola’s “J’accuse”: a series of paragraphs, each beginning with the bolded words “We agree,” pointing out the bill’s many awful features, from the harm it would do to people with pre-existing conditions to the chaos it would cause in insurance markets.

It takes a truly terrible proposal to elicit such eloquent unanimity from organizations that are usually cautious to the point of stodginess. So how did Republicans come up with something that bad, and how did that bad thing get so close to becoming law? Indeed, it still has a chance of being enacted despite John McCain’s “no.”

The answer is that Republicans have spent years routinely lying for the sake of political advantage. And now — not just on health care, but across the board — they are trapped by their own lies, forced into trying to enact policies they know won’t work.

Reporting on why the G.O.P. plowed ahead with Graham-Cassidy makes it clear that many Republicans supporting it are well aware that it’s a bad bill, although they may not appreciate just how bad. “You know, I could maybe give you 10 reasons why this bill shouldn’t be considered,” said Senator Chuck Grassley of Iowa. “But,” he continued, “Republicans have campaigned on this,” meaning repeal-and-replace, and had to fulfill their promise.