Final answer:
The main reason for the internal context, or concern about Communist infiltration, was the political climate in the U.S. by 1950. The House Un-American Activities Committee and the Senate Permanent Subcommittee on Investigations held investigations and hearings on Communist influence, and the Internal Security Act gave the government greater powers to investigate sedition.
Step-by-step explanation:
The main reason for the internal context, or concern about Communist infiltration, was the political climate that emerged within the United States by 1950. The victory of Communist forces in China and the outbreak of the Korean War created a situation where political leaders in the U.S. did not want to be seen as soft on Communism. This led to the House Un-American Activities Committee (HUAC) and the Senate Permanent Subcommittee on Investigations holding numerous investigations and hearings on Communist influence in American society during the early 1950s. The passage of the Internal Security Act also gave the government greater powers to investigate sedition.