What is the definition of "a legitimate legislative purpose?" The word "legitimate" in some contexts can be subjective. One of the most difficult concepts for me is how to be certain about motive/intent.
Inquiry for the purpoose of informing a change in law. Not "oversight" or "to decide whether or not to form a committee on imeachment."
Funny thing is, Congress could pass a law that all tax returns be a matter of public record. They iused to be, but that was mighty unpopular, so they had their political necks on the chopping block. This particular privacy has its foundation in legislation.