In the 1950s McCarthyism looked for communists in the US. Academics were among those under suspicion.
Clay Cochran was an economics professor at University of Oklahoma. He was investigated by the FBI for 10 years for suspected communist ties.
Cochran was likely accused because of his left-leaning politics, anti-establishment attitude, and past work with welfare programs.
Most of his colleagues said he was reliable and loyal to the U.S. But a few disagreed. Some accused Cochran of turning his back to the American flag. Others recalled him saying that the U.S. Government was as bad as Russia or Nazi Germany.
Cochran was denied tenure in 1952. It was partly due to the accusations. You can read the FBI report with Cochran's notes at UW's American Heritage Center.