The nuclear hysteria of the fifties was pumped up by some of the smartest US physicists, especially Edward Teller, John von Neumann, and John Wheeler. Of course lots of others, even smarter, saw through it, including Oppenheimer, Fermi, and Rabi. So did Eisenhower, at least to a degree. Unfortunately, logic and reason have a hard time competing with hysteria, especially when politicians on the make, like Symington and McCarthy join the chorus.
This would be a deterrent—but if the contest to maintain this relative position should have to continue indefinitely, the cost would either drive us to war—or into some form of dictatorial government.
Such intense anxiety demanded alleviation. Conveniently, there was a scapegoat at hand to slaughter.
Rhodes, Richard. Dark Sun: The Making Of The Hydrogen Bomb (p. 529). Simon & Schuster. Kindle Edition.
That scapegoat was Oppenheimer. Teller's hysteria with regard to Oppenheimer was due in part to humiliation. Oppenheimer had mocked him when some of his calculations had left off some huge factors, and Oppenheimer, an arrogant and sarcastic fellow who was also quicker than anyone, was well positioned to puncture Teller's own arrogant but fragile ego.
Oppenheimer's most dangerous enemy, though, was Lewis Strauss, Eisenhower's new head of the AEC. Strauss was a brilliant business man, but also stubborn and arrogant, and had likely also suffered at the hands of Opie's condescension. One of his colleagues described as a man who would consider you a fool if you disagreed with him once, and a traitor if you persisted. Strauss was also a prude: he was scandalized by the fact that Oppenheimer had begun sleeping with his wife Kitty while she was still married to another man. Moreover, he was a conservative and very religious Jew, while Oppenheimer was a liberal and totally irreligious Jew.
Of course his suspicions of Oppenheimer were not totally without foundation. Oppenheimer had described himself as not a Communist but said that he had probably been a member of many of the Communist front organizations on the West Coast. Ultimately though, the evidence adduced against Oppenheimer had far more to do with hysteria than logic.