My theory is the whistleblower is a composite character Democrats created to disseminate their leaks.
While I believe Eric Ciaramella is A whistleblower he's just their a figurehead.
Since he only has his own limited alleged first-hand knowledge he doesn't know all the things every other leaker have given Democrats. Democrats can't risk him testifying because he would fall apart during questioning.
Roberts is a fool to give this any respect or serious consideration.