Freedom of speech is allowed in the U.S, with the only limitations being slander, libel, and incitement. Slander and libel are blatantly lying about something and accusing a person of false charges. The only difference is one is spoken and one is written. (Libel is written and slander is spoken) The senator is allowed to criticize the government, as long as he isn’t accusing them of false statements or lying, he cannot be tried for treason.