That itself also opens them to risks.
Namely, that Trump will double-down on then releasing more on the coup.
In fact, he might actually be doing so, behind the scenes.
At worst, he could go Gotterdamerung all on them.
The point is that the Democrat leadership is willing to drag the country through even more trauma and destruction than Mueller already has and also willing to destroy the Democrat Party at large to try to save the butts of a few high level individuals
Right or wrong, smart or stupid, good or bad has nothing to do with anything at this point. It’s all about a handful of very powerful, very guilty people trying desperately to save themselves without any consideration for the collateral damage they do in the process