Former Senators and US House Representatives, and members of Cabinets and Committees need to come clean with any classified documents they have. Current members of Congress need to be sure classified material is secure and in appropriate and secure places. Any former or current members with classified documents need to inform DOJ and/or FBI.
I don’t think the country knows how extensive this looseness with classified material has been. I am confident our enemies are planning to find out for themselves. Not that after Trump they need any help locating them.
The President should not be the lone determinant of classification either. President Biden should write an addendum to the declassification order. Congress needs to legislate as well as to determining classification and declassification.
