President Donald Trump continued his social media war on his own party Thursday evening, attacking senior House Freedom Caucus members on Twitter.

The Republican president used a pair of tweets to call out Rep. Mark Meadows, the North Carolina Republican who chairs the group, Rep. Jim Jordan, the Ohio Republican who was its first leader, and GOP Rep. Raúl R. Labrador of Idaho. Trump pointedly blamed the trio for blocking a Republican-crafted health care bill that was pulled last Friday.

The president also appeared to prejudge the outcome of a debate on tax cuts and tax code changes that hasn’t even started, saying the same three lawmakers are standing in the way of a tax package that hasn’t even been crafted yet.

If @RepMarkMeadows, @Jim_Jordan and @Raul_Labrador would get on board we would have both great healthcare and massive tax cuts & reform.

— Donald J. Trump (@realDonaldTrump) March 30, 2017

It was Trump’s second Twitter attack of the day on the hard-line conservative group. Around 9 a.m., he attacked the faction — along with Republican moderates — for refusing to support the House Republican legislation to partially repeal and replace the Obama administration’s 2010 health care law. The president and House Speaker Paul D. Ryan canceled a vote on the measure after concluding it lacked the votes needed to pass.

[Trump Ready to Fight House Freedom Caucus]

In a stunning move, Trump suggested he was prepared to launch a GOP civil war by seeking primary challengers to Freedom Caucus members who opposed the health care measure

The Freedom Caucus will hurt the entire Republican agenda if they don't get on the team, & fast. We must fight them, & Dems, in 2018!

— Donald J. Trump (@realDonaldTrump) March 30, 2017

Should the president and the group continue to feud while Democrats opt against handing Trump legislative victories, it could bring a new era of intraparty dysfunction to Washington just when Republicans have been predicting a period of “unified government” and conservative policymaking since the party holds the White House, House and Senate.

White House Press Secretary Sean Spicer explained the morning tweet by saying the president and his top aides, after the health care bill was pulled, will “get the votes from wherever he can” to pass legislation to enact his agenda.

He also indicated that some Freedom Caucus members have let the White House know they are willing to work directly with the president, saying there are “some promising signs on that.”

Trump’s top spokesman also challenged caucus members to act in their constituents’ best interests rather than continue insisting on voting as a bloc. And he urged the group to avoid, while negotiating, legislation letting the perfect become the enemy of the good.

The president met privately with Freedom Caucus members just hours before he and Ryan pulled the health care bill. But the former businessman, whom Spicer had deemed “the closer,” was unable to strike a deal with the group that might have secured the 216 votes needed to pass the bill and hand Trump a major victory on a promise that was central to his successful campaign.

[Freedom Caucus Isn’t Backing Down After Trump Threat]

For their part, Freedom Caucus members spent much of the morning firing back at a president they were among the first elected Republicans to support.

Kentucky Rep. Thomas Massie, who is not a member of the caucus, trolled Trump on Twitter, writing, “It’s a swamp not a hot tub. We both came here to drain it.” He then included one of the president’s signature signoffs: “Sad!” Massie also pointed to the low popularity of the now-defunct GOP health care bill.

.@realDonaldTrump it's a swamp not a hot tub. We both came here to drain it. #SwampCare polls 17%. Sad! https://t.co/4kjygV2tdS

— Thomas Massie (@RepThomasMassie) March 30, 2017

And while answering reporters’ questions about the morning tweets, several Freedom Caucus members questioned whether Trump could find candidates to oust them in primaries, or suggested he would get replacements even further to the right given their dark red districts.