Senators, Congresscritters, and their staff can NOT require the security staff to violate security regulations for matters related to National Defense. They can order around the Capitol Hill Police and other legislative branch employees.
Were I in their shoes, I would refuse to comply with an unlawful order. I would be making phone calls and notes as hard as I could as to who ordered me to do what and when.
National Defense and related matters are the SOLE responsibility of POTUS and, by extension, those he appoints to carryout those duties. POTUS IS the classification authority for the United States. The classification of any information or thing is done in his name. He can declassify ANYTHING at his discretion.
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)