That didn’t take long.

Shortly after Rep. Justin Amash (R-MI) became the first Republican congressman to call for the impeachment of President Trump, a local GOP lawmaker announced he’d run against the four-term congressman.

Amash took to Twitter on Saturday to proclaim the Mueller report shows Trump “engaged in impeachable conduct.”

The next day, Michigan state Rep. Jim Lower (R) announced he’d run against Amash.

“Justin Amash’s tweets yesterday calling for President Trump’s impeachment show how out of touch he is with the truth and how out of touch he is with people he represents,” he said in a statement.

Lower said he’d been gearing up for a run already and planned to announce over the summer, but Amash’s weekend comments had spurred him to jump into the race earlier than initially planned.

Trump met Amash’s criticism with fury over the weekend, calling him a “total lightweight” and a “loser.”

Amash, a libertarian-minded congressman first elected in the 2010 GOP wave, survived a tough 2014 primary challenge with the help of the fiscally conservative Club for Growth as well as the DeVos family, a powerful fixture in Michigan GOP politics (Betsy DeVos is now Trump’s education secretary).

But while his last primary was mostly a test of his hardline fiscal conservatism, this could become the first real electoral test of whether an anti-Trump Republican can survive. Other Trump critics, like Sen. Jeff Flake (R-AZ), opted to retire rather than test that hypothesis.

But Amash has also been considering a run for president on the Libertarian Party ticket, so he may not be around for Lower to run against him.