It is to laugh:
What’s going on here is that institutionalist types are almost literally incapable of admitting to themselves that the Trump administration’s attempted autogolpe happened right out in the open, so all this “investigation” is about as critical as investigating somebody who just walks up and shoots somebody to death on 5th Avenue. In the middle of the day. In front of several hundred people. And on camera.
To pick a hypothetical completely at random.
When is the pretending going to stop?