The Democrats want new witnesses, new documents, and new evidence, because they want a new impeachment hearing altogether. They want the Senate to implement 'Impeachment Hearing Redux'. They want a new second impeachment circus because they failed on the first one. So far, it does not look like the Senate is going to fall for the Democrats three card monte game.
The weirdest part is, the Democrats have proclaimed loudly that they want impeachment ongoing forever. They have said they are never going to stop, innocent or not. They don't care about facts or due process. So why would the Senate grant their stated wish to keep impeachment ongoing for as long as Trump is President? Why would the Senate play Pelosi's game?
They should just kill this farce and get back to real work.