Here's the thing. They knew there was a risk of public seeing something actually easy to digest among the testimony and documents that were withheld. They knew there was a chance of him losing the base or else they wouldn't have pulled out all the stops to prevent that. And the insane thing is that they'd still have Pence, so it's the precedent they needed to prevent, because once one R politician is actually held accountable, it'd just be a matter of minutes before they all were.
Bolton does have a certain gravitas in conservative circles. By the time his book comes out he'll be a dirty stinking rat, a RINO and all kinds of mean nasty ugly things. A turncoat & a traitor to the cause, whatever that is.