Senator McCarthy’s influence might have died quickly following his 1950 accusations had it not been for

The arrest and trial of Julius and Ethel Rosenberg, who were accused of passing atomic secrets to the Soviet Union, intensified public fears about communist espionage. That atmosphere helped keep McCarthy’s accusations influential after 1950. The other choices do not fit: no hundreds of communists were discovered in the administration, Truman was not defeated in 1956, and Hollywood blacklisting was part of the broader Red Scare rather than the key event that sustained McCarthy’s influence.

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