Described as "one of the country's most prominent political reporters during the 1960s," Vanocur served as White House correspondent and national political correspondent for NBC News in the 1960s and early 1970s. He was one of the questioners at the first of the Kennedy-Nixon debates in 1960, as well as one of NBC's "four horsemen," its floor reporters at the political conventions in the 1960s—the other three were John Chancellor, Frank McGee, and Edwin Newman. While White House correspondent during the Kennedy administration, Vanocur was one of the first reporters to publicly ask Kennedy to justify the failure of the Bay of Pigs Invasion. Vanocur also dubbed Kennedy's coterie the "Irish mafia."