Would the VP (Pence) be the tie breaking vote if it came to that ???
No need for tie breaker, unless Roberts wants more witnesses.
50-50 is not a majority, so whatever is proposed (more witnesses) doe not have majority support.
Odds are that the senate will vote 49 for more witnesses. This is also not a majority.
I don’t think Roberts wants to spend any more time in the loonie-bin known as the senate, than he has to.