The political answer to your question is that the voters can "impeach" their own Senators and Representatives every November.
My read of the Constitution is that (if there was the political will) the U.S. House of Representatives could draw up and pass Articles of Impeachment for individuals in the Senate, to include the leadership. (What Constitutional amendment “locks out the HoR”? - correction welcomed!)
AND (if there was the political will) the Senate could try the impeachment and vote to remove the offenders from office...
But if they won’t even hold the current executive accountable for the innumerable violations of law it’s committed, do you think they’ll self police?