First, this IS a legal proceeding analogous to an indictment/trial process. Second, the impeachment is essentially an indictment, where the only question is does the prosecution have a case that should go to trial?
Have you never heard the lawyers' expression "you can get an indictment against a ham sandwich"? It is NOTORIOUSLY easy to secure an indictment.
So, no. No way in hell would a judge actually throw this out. The evidence is there, the case is there, and if you want to argue against all of that, the proper thing to do is to let the case go to trial.