President Donald Trump took to Twitter Thursday morning to vow to “fight” members of his own party in the 2018 midterm election.

Trump aired lingering grievances with the conservative lawmakers in the House Freedom Caucus for their rejection of the health care bill he supported, the American Health Care Act. Freedom Caucus members said that the bill did not fully repeal Obamacare, as they had promised their constituents. Republican leadership ultimately pulled the bill when they failed to earn the number of votes they would need in order to pass it.

Although moderate Republicans outside of the Freedom Caucus also objected to aspects of the bill, Trump appeared to lay blame solely on lawmakers in the Freedom Caucus for the bill’s failure.

“The Freedom Caucus will hurt the entire Republican agenda if they don't get on the team, [and] fast,” Trump tweeted. “We must fight them, [and Democrats], in 2018!”

Some Twitter users questioned whether showing animosity toward members of his own party would help the president on other aspects of his agenda.