The Senate will not vote for impeachment, but they and Mitch will be taught a lesson in procedure by the Chief Justice, who under law presides over the trial. Once the Chief Justice is sworn, Mitch no longer has a special place in this proceeding. The Chief Justice has a great deal of latitude during the proceeding, up to the point of calling witnesses. One must remember this constitutional process is a vehicle by which the president is held to account.
I keep hearing complaints about the closed committee meetings during the run up to the public investigation. The privacy of these meetings (prior to impeachment) was a practice during the Clinton impeachment and certainly consistent with the analogy that the hearings were part of a discovery phase. Just as discovery during a lower court trial is not make public until trial. The actual impeachment trial is the responsibility of the Senate presided over by the Chief Justice.
Of course even a no vote doesn’t stop the other house committees from continuing their investigations into the presidents finances.