Answer: Joseph McCarthy
Senator Margaret Chase Smith is most likely referring to Senator Joseph McCarthy and his attack on those he considered communist traitors.
Joseph McCarthy embodied the fears that many people had surrounding communism during the Cold War. He accused government employees, university professors, Hollywood celebrities and people in various industries of being Communist sympathizers, and therefore, "traitors." The accused often lost their means of livelihood, reputation and careers. In this excerpt, Senator Smith is accusing McCarthy of persecuting people who are exercising their freedom of speech. She also condemns the fact that reputations and lives have been ruined without these people ever committing a crime or being judged by a jury.