Possible Clues:

• Name on a 1950s campaign button
• 34th Prez
• 'South Park' brother
• Two-time defeater of Adlai
• 1950s headline nickname
• Dick was his running mate in '52 and '56
• 20-Across nickname
• Nixon was his veep
• 1950s president, familiarly
• Likable candidate