He is a Democrat.
If the democrats retake the Senate, then Senate Majority Leader Chuckie Schumer will never allow another Trump nominee to get to the floor for a vote. If the democrats retake the House, then the first order of business for Speaker of the House Pelosi will be passing articles of impeachment against President Trump.
The time for knocking out RINOs is in the primaries. In the general election, if your only choice is a RINO or a democrat, vote for the RINO, and then work like hell in the next primaries to have better choices.