It’s easy to forget why, exactly, many House Republicans talked about trying to impeach President Joe Biden earlier this year, but the weird crusade was rooted in a scurrilous accusation: The Democrat, GOP officials claimed, was the beneficiary of a weird Ukrainian bribery scheme.

The story never really made any sense, but several congressional Republicans nevertheless took the claims seriously — and when pressed to justify their efforts, they pointed to an informant who brought the bribery allegations to the attention of the FBI.

Whatever became of that informant? I’m glad you asked. The New York Times reported:

A former F.B.I. informant accused of fabricating a claim that President Biden and his son Hunter were each paid a $5 million bribe by a Ukrainian oligarch has agreed to plead guilty to a range of federal charges, according to a court filing on Thursday. Alexander Smirnov, a profiteer, fixer and gossip based in Las Vegas, reached a deal with the special counsel overseeing the investigation into Hunter Biden, David C. Weiss, that could lead to 48 to 72 months in prison, according to the filing in federal court in California.

The trouble began in earnest in February when Smirnov was indicted for providing “false derogatory information” to the FBI about Biden and his son. The charges stemmed from the special counsel investigation led by David Weiss, a Trump-appointed prosecutor.

Reporting on the developments shortly after the indictment was announced, MSNBC’s Chris Hayes described this as “the most spectacular embarrassment imaginable” for the Republicans who targeted the president, and it’s worth understanding why.

For Biden’s GOP detractors — on and off Capitol Hill — Smirnov’s claims were foundational. He was the party’s star witness. Sean Hannity’s Fox News show ran with this informant’s claims in at least 85 separate segments last year. The Republicans’ entire “bribery” conspiracy theory was based on the claims of one man — who was charged with lying to the FBI about the Bidens.

Making matters worse, the GOP’s anti-Biden witness, soon after getting indicted, conceded to prosecutors that some of the false information he spread came from “officials associated with Russian intelligence.”

Ten months later, according to the latest court filings, Smirnov is pleading guilty to the federal criminal charges.

I’m mindful of the fact that Smirnov is not exactly a household name, and this story probably won’t appear on the front pages of many newspapers, but the developments represent a stunning fiasco for some prominent GOP lawmakers.

Rep. Jim Jordan, for example, the chair of the House Judiciary Committee, is on record publicly declaring that he was relying largely on Smirnov’s claims as part of his pursuit of Biden. The Ohio Republican specifically told Fox News in January that the allegations raised by Smirnov represented “the heart” of the GOP’s case against the president.

Rep. James Comer of Kentucky, the GOP chair of the House Oversight Committee, made similar comments, declaring last year that Smirnov’s claims were “a very crucial piece of our investigation.”

At least one House Republican conceded that the party was warned not to take these uncorroborated anti-Biden allegations seriously, but Jordan and Comer, among others, ignored the advice and ran with the claims that have since collapsed.

In the GOP’s impeachment crusade, the real “scandal” isn’t what Joe Biden did, it’s what his accusers did.

This post updates our related earlier coverage.