Well...it can be a bit complicated. The broader, less-specific the request, the more likely it is that the 5th Amendment will protect him.
The Fifth Amendment only applies to testimony, or to actions that have a testimonial component. For example, you cannot refuse to supply a blood sample or DNA based on the Fifth Amendment because it goes to the existence of an independent, pre-existing fact --characteristics of your blood. Generally, the production of pre-existing documents doesn't constitute "testimony", though being asked to authenticate the documents, or to create documents that don't already exist, would be protected under the 5th.
BUT, the broader the subpoena, and the more effort (especially mental effort/decision-making) that a witness must do to identify and locate the documents, the more likely it is that their production can be shielded by the 5th. So for example, if a witness was directed to produce
specific documents already known to exist, that probably isn't protected. But if they're told to "turn over all documents that have to do with your dealings with Russians", I'd say there's a pretty good argument that is protected. That's kind of what happened with Webster Hubbell, and the Supreme Court ordered the dismissal of the indictment based on those documents because he was required to comply with the subpoena over his 5th Amendment objections.
The other complication is that if some of the documents exist and are possessed by any business corporation he created, they don't have Fifth Amendment rights, so they could be compelled to produce those documents even if he cannot be compelled personally. But there would have to be a separate records custodian or individual in possession, custody, or control of those documents for that loophole to exist.
As I said, it's a bit complicated....
@the_doc
