Nixon vs. Clinton
As heard on The Phil Valentine Show

Nixon: Watergate
Clinton: Waterbed

Nixon: His biggest fear was the Cold War
Clinton: His biggest fear is the cold sore

Nixon: Carpet bombing
Clinton: Carpet burns

Nixon: Couldn't stop Kissinger
Clinton: Couldn't stop kissin' her

Nixon: His Vice President was a Greek
Clinton: His Vice President is a Geek.