No, I think they are backed into a corner and have to exclude those key witnesses to actual Dem crimes so Radcliff couldn't expose the thruth while they are testifying under oath. That and shut down any line of questioning of witnesses by Radcliff leading to any implied wrongdoing by Dems. Its a show by the Dems, the inevitable outcome is that they will impeach Trump. Then it moves to the Senate where the witnesses and the process will get a thorough examination and Trump will be fine.