Let's see what he has to say. It just seems weird to be able to initiate this and be able to throw up your hands and say "no questions!"
It's not weird. If we compare this to a trial, civil or criminal, the only witnesses who are allowed to testify at trial are: (a) people who witnessed relevant things, or (b) people who have expert opinions about relevant things.
In the whistleblower's case, he already told us in his report that he didn't witness anything relevant. He knows only what other people (who did witness things) told him. Also, nobody's claiming that he's an expert on what is or isn't impeachable.
Let's say we call him to testify. How would the testimony go?
Q. Tell us whatever you know.
A. Mogadishu is the capital of Somalia.
Q. No, what things relevant to the impeachment inquiry do you know? Do you have reason to believe that Trump did impeachable things?
A. I'm not an expert on what constitutes an impeachable act, but I have reason to believe he did things that are rather troubling.
Q. Did you see him do troubing things?
A. Me? No.
Q. Then what's your basis for believing that he did troubling things?
A. The Vindman guy told me that he saw Trump do very troubling things.
At this point, we really care about what
Vindman claims to know. We care about Vindman's substantive claims, we care about how well he seems to remember what he saw, we care about whether his observations seem to be accurate, and we care about his truthfulness. We're not going to get very far talking to the whistleblower about those things ... we need to hear from Vindman himself. Second-hand information doesn't count when first-hand information is available. In a court, if the whistleblower tried to testify about what Vindman told him, it would generally be inadmissible.
Getting information from the whistleblower is important so we know who the actual witnesses should be. That was the point of the whistleblower's report. But now that we're holding hearings, we want to hear from the actual witnesses.
Courtroom rules of evidence don't strictly apply to these hearings, and I do think there's one important exception to everything I just wrote.
Q. What's your basis for believing that Trump did troubling things?
A. John Bolton told me that he saw Trump do very troubling things.
In this scenario, we really want John Bolton's testimony. But what if we can't get it? What if Bolton refuses to testify based on instructions from the White House? And what if we can't get a court to order him to testify in a timely manner, or what if he violates such an order?
In that situation, whether the whistleblower should be called to testify becomes more complicated. Now his testimony might be the best way to find out what John Bolton knows, which seems kind of important. So now we have to weigh competing interests against each other -- the whistleblower's privacy versus the national importance of the information he might have.
But absent a situation like that, I think it's a pretty easy call to pursue direct testimony rather than hearsay.
