The Reps need to grow a spine and tell the Dems and their allies in the media to stuff it, or it will be the Kavanaugh hearings all over again. If Bolton falls through and can't directly link Trump to anything, much like Sondland couldn't do, there will just be another thing that needs looked at, and then another thing, and another, and another. It will go on and on. It will never be enough for the Dems, because they know they are going to lose this no matter what, and just want to drag it out to as close as the election as possible.
Tell them to get fucked, wrap this up, and let the chips fall where they may come November.