Historical clue formulations

• Comedian who said "In America, anyone can become president. That's the problem" — 2018-12-11
• "Seven Words You Can Never Say on Television" comedian — 2018-08-10
• Comedian with the 1972 album "Class Clown" — 2013-04-24
• Comic who quipped "Weather forecast for tonight: dark" — 2011-01-04
• See 3-Down — 2006-07-30
• See 35-Across — 2003-06-05