I think a lot of it comes down to what Cohen says, how factual it is (what evidence backs it up), when the crimes supposedly occurred, etc, etc, etc. As we have seen in a number of venues, just because someone accuses another of some crime, doesn’t mean it actually happened or that there is any proof to back up the claim. If Cohen says anything about Trump committing crimes, though, you can bet the Dems will go crazy and start chanting for impeachment.