Amash, a member of the Republican Party's libertarian-leaning Freedom Caucus, tweeted his slight to Trump after the president said the Freedom Caucus would be a threat to the GOP going forward into the 2018 midterm elections.
No one is laughing now.
Trump attacked the group of conservative lawmakers over Twitter Thursday, saying they "will hurt the entire Republican agenda" and "we must fight them". But in the end, majority decided it wasn't enough and said they'd vote against the bill.
The Freedom Caucus claims to have about 40 members, most of whom are considered to be on the far-right side of the Republican Party. He grouped its members, all of them Republican, with Democrats in calling for their political defeat - an extraordinary incitement of intra-party combat from a sitting president.
"We had no votes from the Democrats", the president lamented. "We're not going to give up after seven years of dealing with this".
Over the past week, however, his attitude has shifted.
"Democrats are smiling in D.C. that the Freedom Caucus, with the help of Club For Growth and Heritage, have saved Planned Parenthood & Ocare!" he wrote on March 26.
Some conservatives outside the Freedom Caucus bristled at Trump's remarks about the bloc.
Now it appears the president is preparing for all-out war against the intransigent congressmen - and it's a fight they seem willing to join. On Thursday he threatened primary challengers in a tweet.
Justin Amash, took aim at the president's oft-repeated desire to "drain the swamp" in Washington, a phrase meant to evoke Washington lobbying, big money in politics, and corruption.
Who in the Republican Party is Trump talking about?
There are about three dozen members of the Freedom Caucus, and a lot of them were elected or re-elected comfortably in solidly Republican districts. And let's be clear: What comes out of investigations into Team Trump and Russian Federation has much greater capacity to make or break Trump's presidency, personal reputation and more, than any healthcare reform bill that anyone will conjure up.
"The Democrats aren't for repealing Obamacare". Even if it had, several Republican senators had expressed reservations about it. "I have no doubt that that's gonna happen very quickly", President Trump said. That is such an easy one.
This set off its own series of tremors in Washington politics.
White House officials declined to elaborate on Trump's tweet. They stand for minimal regulation, lower taxes and smaller government. "You know why? I want a patient-centred system. Now, I want this thing gutted". When I saw her at the Capitol this week, Pelosi was in a surprisingly good mood.
"We have come a long way in our country when the speaker of one party urges a president NOT to work with the other party to solve a problem", he tweeted.
Trump's tweets, showing an increasingly aggressive and hard-edged view of the Freedom Caucus, represent his own unfiltered take on a group that is viewed inside the White House as threatening ambitious agenda.
Poe's exit is the group's first defection since it emerged in 2015.
Traditional partisan battle lines may at least temporarily re-emerge next week, when the Senate votes on seating Neil Gorsuch to the Supreme Court. Republicans control the White House and both chambers of Congress, so we're basically in their hands.
In a letter to the president, Democrats said they'd be happy to work with him on healthcare, if "you abandon your efforts to repeal the Affordable Care Act" and "you rescind your ACA executive order signed on January 20" - neither of which would fly with Republicans.