The correct answer is the following.
One unexpected effect of the Alger Hiss spy case was that it helped to promote the political career of Richard Nixon.
Alger Hiss was accused of being a Soviet Spy in 1948. Before this, he participated in the establishment of the United Nations.
In 1947, Richard Nixon was a Congressman for the state of California During the committee sessions he argued that Hiss cannot be proved to be a Communist. Nixon’s participation in the case helped him to get a seat in the Senate. He considered that as a define moment in his career. After being Senator, he became Vice president under Dwight Eisenhower.