Is Trump the first president to violate the PRA? Not a chance. This is a perfectly normal and routine bureaucratic process that is being weaponized to suit the agenda of the radical Left and its mainstream media allies.
It's clear why Congress was denied access to the materials: to protect what's obviously an open and ongoing investigation into the twice-impeached former President. He stole classified intelligence and stored it at his unsecured country club - a magnet for foreign intelligence agents.
Merrick Garland's DOJ has proven itself to be excessively timid when it comes to dealing with the potential crimes of the previous administration. While the DOJ can't comment on an open and ongoing investigation, there's no sign that any meaningful investigation is actually happening, at least not in a timely manner.