Final answer:
McCarthy can be considered the main reason for political fear due to his tactics of making unsupported accusations without evidence, known as McCarthyism, which created a climate of fear in which few Americans were willing to challenge him.
Step-by-step explanation:
McCarthy can be considered the main reason for political fear as a result of the power that he held because of his tactics of making unsupported accusations against individuals without providing evidence, which became known as McCarthyism. McCarthy's tactics, such as bullying witnesses and using intimidation and innuendo, created a climate of fear in which few Americans were willing to challenge him. This fear extended to presidents as well, as even President Eisenhower avoided confronting McCarthy directly.