The Constitution gives the power of impeachment SOLELY to the House of Representatives. To impeach, evidence and testimony is gathered, then formulated into an article of impeachment that the House must then present to the Senate for final judgement. "New" evidence would fall under the evidence/testimony gathering phase of an impeachment and not the final judgement phase that only occurs when the House presents an article of impeachment to the Senate. In this particular case, the House is the party responsible for developing any new evidence or testimony and formulating that into it's own article of impeachment. No one in the Senate can keep them from doing this just like no one in the house can force the Senate to do this. According to the roles of the impeachment process assigned to the House and Senate, the Senate cannot develop evidence, it can only judge an article of impeachment as delivered by the House. An impeachment is not like a normal trial.
Right, which is most akin to the indictment process in a criminal trial.
Criminal trials introduce new witnesses and evidence all the time that never went to the grand jury.
According to the roles of the impeachment process assigned to the House and Senate, the Senate cannot develop evidence, it can only judge an article of impeachment as delivered by the House
The Senate has the sole right to try the case.
What part of that formulation limits the trial to be something much less than all other trials in our system?