Final answer:
Senator Joseph McCarthy's claims about Alger Hiss were part of his pattern of making unsubstantiated accusations during the Red Scare. He used fears of communism to suggest that Hiss was a communist influence within the State Department, contributing to the atmosphere of McCarthyism.
Step-by-step explanation:
When addressing the question of what Senator Joseph McCarthy suggested about Alger Hiss, it is important to understand the historical context. McCarthy was known for making unsubstantiated accusations during the period known as the Red Scare, when fear of communism was at its height. Specifically, McCarthy accused various individuals within the State Department of being communists without providing solid evidence, a tactic that became synonymous with McCarthyism. McCarthy's claims regarding Hiss heavily implied that he was a communist influence within the government, though his tactics were often deceptive and lacked credible supporting evidence, as seen in his fluctuating numbers and vague allegations. Therefore, his suggestion that Hiss influenced the Yalta Conference in favor of the Soviets was effectively a part of his pattern of unsubstantiated allegations, aiming to exploit fears of communism for political gain rather than being based on confirmed facts.