is because the know that it's only a matter of time (and not much of it!) before tRump does something as egregiously illegal and outrageous as he has been emphatically exposed and impeached for (and the know the list of Articles could have a lot longer). They, as Pelosi has said, know that "tRump is self-impeaching" on virtually a daily basis. They want to get this over with so they can trumpet out the clarion call tRump exonerated! Of course, they realize with this clown car cavalcade of exploding missteps, that he'll just continue doing what he's been doing his entire execrable existence, but I think they hope (with bated breath) that he won't be exposed before the election. The more he does what he does, the closer the election looms and to try to excuse and explain the behavior becomes increasingly more challenging for them to morally and logically defend.