https://www.politicususa.com/2018/12/08/trump-blumenthal-indicted.html

Trump lost it on Twitter and began attacking Sen. Richard Blumenthal (D-CT) after the former prosecutor said that Trump and his family can be indicted.
Blumenthal said, “The pieces of the mosaic or the puzzle are coming into place, and the walls are closing in on Donald Trump, and his inner circle, including his family….I may be in the minority, but I believe the president could be indicted and the trial could be postponed until after he finishes service….I think the report will be extraordinarily damning, whether or not there’s an indictment.”

We are already seeing black and white charges that he's listed in as "Individual 1" that Cohen pleaded guilty to, where "Individual 1" directed the guilty felon to perpetrate campaign violations.

Mueller can wrap up those charges with lying to the public (which is impeachable) about those violations (which are impeachable). Congress is not in a position to refuse to uphold the law against black and white clear cut criminal violations.

"After he finishes service" will be after he is impeached, which will not be at the end of his term. The GOP cannot afford that during the year run up to 2020.