Donald Trump’s allies have launched a super PAC that will seek to oust Rep. Thomas Massie, a Kentucky Republican who opposed the president’s domestic policy bill and criticized his strikes on Iran’s nuclear facilities.

The Kentucky lawmaker says the president’s threats over Iran and tax-bill stances aim to keep other Republicans in line.

Republican lawmakers are steering clear of the intraparty showdown, with Trump’s team targeting Massie for defeat in next year’s midterm elections.