Has there ever been an impeachment in the Senate without any witnesses called?
The case & the evidence should have already been done in the HoR as support for bringing impeachment charges...........IOW, the case should already be fully prepared.
The case should simply be presented as is, to the Senate, not being able to call new witnesses unless the defense desires to call them since they were not allowed to call any in the HoR.
Prosecution should already have made their case.
MM
