Conversation so far:
What types of things was Linus Pauling criticized for?
peace activism, his frequent travels, and his enthusiastic expansion into chemical-biomedical research all aroused opposition at Caltech.
Who opposed his works?
scientists who appreciated the contributions that he had made in chemistry, disagreed with his political positions and saw him as a naive spokesman for Soviet communism.
What political positions made him unpopular?
Pauling was referred to not only as a collaborator, but as a "fellow traveler" of proponents of Soviet-style communism.

Question: Is there anything else unique about his political beliefs?
Self-contained rewrite: Is there anything else unique about Linus Pauling's political beliefs other than promoting Soviet-style communism?