Tensions inside the House Democratic Caucus are running high after an ugly debate last month over legislation to provide emergency aid for the humanitarian crisis at the border. Progressives lambasted leadership and some centrists who backed the measure as “child abusers” because it lacked money to improve hygiene and nutrition standards for detained children migrants.

That Democratic firefight and others have inflamed liberals looking ahead to 2020, including the group that was behind now-Rep. Alexandria Ocasio-Cortez’s upset win last year. The raw emotions have many in the party wary of an all-out battle for the party’s soul in primaries from the presidential race all the way down to the congressional level.

“Members are looking over their shoulders,” said Rep. John Yarmuth (D-Ky.), the chairman of the House budget committee.

The list of Democrats facing primaries is growing as the restive liberal base fights hand-to-hand in skirmishes across the map.