From John Cornyn’s office: some of the harshest critics of Gitmo haven’t been there. These are the senators who have:
Cantwell
Chambliss
Cornyn
Dewine
Graham
McCain
Ben Nelson
Sessions
Levin
Hatch
Corzine
Having not gone down does not mean you can’t criticize, it’s just an interesting fact.
UPDATE: Four more went down while it was being put together:
Inouye
Hutchison
Stevens
Feinstein