The important consideration when it came to Bolton is not whether he would physically show up in the Senate chamber, take the oath, and give testimony. It was whether his testimony would change anything. It wouldn’t. If he testified in a manner that is consistent with press reporting about his soon-to-be-published memoir, it would prove that the president pressured Ukraine for investigations.
The House managers have already proved that.
There is no need to belabor the point. The Democrats’ problem is not that they’ve been stopped from proving their case. They did prove their case … but their case is, at best, a petty crime, while impeachment is akin to capital punishment. It’s not that we approve of petty crime; it’s that petty crime is not a capital case. And even if Bolton testified, it wouldn’t become one.