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.

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

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