Possible Clues:

• First name in 1950s headlines
• -- Stevenson, 1900-1965, US statesman
• Big name in 1950s presidential campaigning
• '50s foe of Dwight
• U.N. ambassador under John and Lyndon
• Dwight's campaign opponent
• Dwight's opponent in 1952 and '56
• Old veep Stevenson
• 'Madly for ___' (1952 campaign slogan)
• 1950s campaign name