All's Fair is a 1976 sitcom aired on CBS, developed by Norman Lear. It starred Richard Crenna as conversative political columnist Richard Barrington III and Bernadette Peters as liberal photographer Charley Duke, who fall for each other despite their differing ages (Barrington was 49, Duke was 23) and politics. Mid-season, Michael Keaton joined the cast as Lenny Wolf. The series aired Mondays at 9:30 Eastern time, and ran a full season before it was cancelled. In the 40+ years since its last airing, only the opening credits have been seen, although there are plenty of people who remember the show well.
Edit: The series was fully found.