There’s a couple things at work here ...
They want the Senate part done early, so those Dem Senators that are currently campaigning won’t be off the trail too much
But there’s also the real possibility of RBG passing soon, which would start a quick Senate confirmation process ... which the Dems would then love to interrupt / delay with their “impeachment” circus
Mitch could dismiss all these bogus charges real quick if he wanted to, simply based on the lack of due process ... next few months will be interesting!!
If RBG were to pass before the end of the year, it’d really toss this whole impeachment process for a loop. You’d have a whole new drama in the replacement process, taking weeks of precious time.
Regarding your comment about RBG, I have been saying this for months. And if she passes away or resigns soon, everything including impeachment will be second and third banana to her replacement. The dems and media (I know, redundant) will be screaming that Trump has no right to nominate anyone … and he will just laugh and do it anyway.