Impeach him for what though?
They also don't have control of the Senate. They'd have to get control in Nov.
Impeach as a stall tactic, not to actually have him removed. There's really no time to f*ck around anymore, Trump will take this to SCOTUS, if it's 6-3, there won't be another shot. Basically they need to play by the same rules Republicans play -- anything goes.
And he has committed plenty of impeachable offenses. Take your pick, the basket is full.