Congressional Republicans on Tuesday warned President Trump not to fire Attorney General Jeff Sessions, fearing it could be the first step in an attempt to kill the federal investigation into Russian meddling in the 2016 elections.

Republicans have tried mightily to ignore Trump’s politically-charged tweets and the rest of the drama coming from the White House, leaving the Russia probe, which could implicate the president or his campaign, to their colleagues on the House and Senate intelligence committees that are running parallel inquiries.