There is no indication that Mitch McConnell and his Republican majority in the Senate are going to let the impeachment trial turn into a wide-ranging free-for-all.
Democrats desperately want to try to rescue their woefully inadequate impeachment case by locating evidence outside the record on which impeachment was based. At the same time, some Republicans wish for the day they can get Joe Biden, Adam Schiff and other Democrats on the witness stand.
Nancy Pelosi is playing games by holding back the articles of impeachment, and there is a good argument that Republicans should not play her waiting game and should just call a trial and get it done with on the basis of the record from the House. Kimberley Strassel writes, Pelosi’s Rolling Impeachment.