Explaining why he decided to keep J. Edgar Hoover as FBI director, Lyndon Johnson famously said, “Well, it’s probably better to have him inside the tent pissing out, than outside pissing in.” That’s a philosophy that House Minority Leader Kevin McCarthy and other Republican leaders might want to keep in mind.

Just look at McCarthy’s response to Michigan Republican congressman Justin Amash, who endorsed impeaching President Trump over the weekend.

Here are my principal conclusions:

1. Attorney General Barr has deliberately misrepresented Mueller’s report.

2. President Trump has engaged in impeachable conduct.

3. Partisanship has eroded our system of checks and balances.

4. Few members of Congress have read the report. — Justin Amash (@justinamash) May 18, 2019

McCarthy responded by alleging the Michigander “wants to have attention.”

“You’ve got to understand Justin Amash,” he said. “He’s been in Congress quite some time.” (Amash took office in 2011, as McCarthy was beginning his third term.)

“I think he’s asked one question in all the committees that he’s been in,” continued the House Republican leader. “He votes more with Nancy Pelosi than he ever votes with me. It’s a question whether he’s even in our Republican conference as a whole.”

Technically, it’s not a question: Amash is a registered Republican who ran as a Republican and has caucused with Republicans for his entire career. But McCarthy raises an interesting thought experiment: What if the GOP kicked him out?

Amash has been rumored to be considering a primary challenge against Trump in 2020. If he does decide to run, he’ll pose more of a threat to Trump than Bill Weld does, given his appeal to younger, more libertarian-minded Republican voters. Any effort to make him feel less secure in his current office only makes the relative cost of running in a presidential primary that much lower.

Even if he decides to forgo the primary battle, an outcast Amash could still stick a wrench in the spokes. He could run for president as an independent and campaign only in Michigan. Trump beat Clinton there in 2016 by a mere 10,704 votes out of more than 4.5 million cast. It’s not unthinkable that Amash could deliver the state to the Democrats. He defeated his Democratic opponent 54-43 in the 2018 midterm, a Democratic wave year.

A few thousand votes can make a big difference. With Michigan’s 16 electoral votes subtracted from Trump’s 2016 haul, Trump would have a 20-electoral-vote margin of victory (including two faithless 2016 electors from Texas). Losing Pennsylvania alone (he presently trails all major candidates except Beto O’Rouke) would knock him down to 270. Losing Arizona and North Carolina would deny him an electoral majority. So would losing Florida alone. Trump currently has negative approval ratings in all of these states, plus Wisconsin, Iowa, and Ohio, per Morning Consult.

And he’ll have plenty of ground to defend if current trends continue. Trump currently has net approval of 3 points or lower in Indiana (11 electoral votes), Georgia (16), Texas (38), Kansas (6), Montana (3), and Alaska (3).

So maybe now isn’t the best time to be kicking people out of the tent.