Republican Rep. Ken Buck gave the political world a jolt last fall when he announced he wouldn’t seek re-election in 2024. This afternoon, the Colorado Republican went a step further: Buck is resigning from Congress altogether — next week.

The GOP congressman’s written statement read:

“It has been an honor to serve the people of Colorado’s 4th district in Congress for the past nine years. I want to thank them for their support and encouragement throughout the years. Today, I am announcing that I will depart Congress at the end of next week. I look forward to staying involved in our political process, as well as spending more time in Colorado and with my family.”

He did not elaborate as to his potential next steps, or what precipitated this sudden and unexpected announcement.

Buck apparently did not even pay his own party’s leaders the courtesy of a conversation. “I was surprised by Ken’s announcement,” House Speaker Mike Johnson told reporters. “I look forward to talking to him about that.” (A spokesperson for Buck told Politico that Buck left the speaker a voicemail message about 30 minutes ahead of time.)

Given the practical implications, Johnson and other GOP leaders have every reason to be disappointed, their occasional clashes with Buck notwithstanding. As things currently stand in the chamber, the House now has 219 Republicans, 213 Democrats, and three vacancies. In terms of the legislative arithmetic, that means that on any given floor vote, it takes 217 members to pass the legislation.

Barring a sudden change of heart, Buck’s departure will lower the Republican majority to just 218 members.

Let’s not forget that Johnson and his leadership team have spent recent months struggling mightily to complete basic legislative tasks. A recent Punchbowl News report concluded, “This is the most chaotic, inefficient and ineffective majority we’ve seen in decades covering Congress.”

That was nearly a month ago. Now, Republican leaders’ challenges are poised to become slightly worse.

Complicating matters for Republicans is that their majority is so small that it occasionally doesn’t exist at all. With some members occasionally having an illness or a family emergency, there are days in which there are actually more Democrats on the House floor than Republicans — which happened about a month ago.

As for the departing incumbent, it was difficult to imagine these circumstances in the recent past, though Buck’s announcement didn’t exactly come out of nowhere.

Circling back to our earlier coverage, after nearly a decade on Capitol Hill, the Coloradan — a member of the House Freedom Caucus — earned a reputation as one of Congress’ most far-right members. This posture, however, was not without limits.

As a Washington Post analysis noted last summer, Buck questioned the merits of GOP impeachment-related efforts, backed the FBI in the midst of a Republican offensive against federal law enforcement, and took Donald Trump’s indictments seriously when his party did the opposite.

In the months that followed, the congressman ignored intra-party pressure and kept going.

For many of his GOP colleagues, this could not stand. A variety of Republican insiders began working weeks ago on recruiting a primary challenger to take on Buck, and members such as Rep. Marjorie Taylor Greene said she wanted Buck to be removed from the House Judiciary Committee and the conference’s whip team.

The right-wing Georgian told CNN in September there was an “unbelievable” level of frustration with Buck within the conference, and CNN’s Melanie Zanona said the “knives are out” for the Coloradan.

It’s against this backdrop that Buck has decided to walk away.

When it comes to the positions the Republican took that outraged his far-right colleagues, it’s important to keep in mind that much of what he’s said has been true. But Buck’s GOP critics haven’t said that they caught him lying; they’ve said that they caught him rejecting Republican talking points — which in their eyes, is vastly worse than lying.

For too much of the congressional GOP, dissent is neither welcome nor tolerated. Buck’s willingness to stick to some of his principles effectively ended his career, which says more about the state of his party than his positions.

This post updates our related earlier coverage.