[266][267] In December 1953, Eisenhower learned that one of America's nuclear scientists, J. Robert Oppenheimer, had been accused of being a spy for the Soviet Union.[268]  Although Eisenhower never really believed that these allegations were true,[269] in January 1954 he ordered that "a blank wall" be placed between Oppenheimer and all defense-related activities.[270] The Oppenheimer security hearing was conducted later that year, resulting in the physicist losing his security clearance.[271] The matter was controversial at the time and remained so in later years, with Oppenheimer achieving a certain martyrdom.[267] The case would reflect poorly on Eisenhower as well, but the president had never examined it in any detail and had instead relied excessively upon the advice of his subordinates, especially that of AEC chairman Lewis Strauss.[272] Eisenhower later suffered a major political defeat when his nomination of Strauss to be Secretary of Commerce was defeated in the Senate in 1959, in part due to Strauss's role in the Oppenheimer matter.[273]
In May 1955, McCarthy threatened to issue subpoenas to White House personnel. 