Former federal prosecutor Andrew McCarthy devotes a National Review Online column to issues surrounding potential testimony from President Trump in the ongoing “Russian collusion” investigation.
[I]f Trump were a journalist rather than the president, everyone would understand that a prosecutor may not just willy-nilly issue a subpoena. Justice Department rules would require the prosecutor to establish both that a serious crime was under investigation and that the journalist had critical information for which there was no other source — and even then, the Justice Department might well instruct the prosecutor not to issue a subpoena.
Obviously, the president’s job is more consequential to our society — to our governance, to national security, to law enforcement — than that of any individual journalist. Therefore, the president should never be diverted from his responsibilities by the demands of a criminal investigation unless there are equally dire reasons. A prosecutor does not get an interview just because the president’s testimony might be relevant or interesting. It has to be make-or-break, in connection with a major offense.
Here, Mueller has not come close to satisfying these conditions — certainly not publicly. …
… I do not believe Mueller can make the showing that should be required before he gets to interview the president. At a minimum, though, the special counsel should be compelled to establish that his obstruction theory is sound. If there is no crime, there is nothing to discuss.