Bruce Mehlman, at Mehlman Consulting, has put together this data showing a dramatic shift that takes place in the late 1960s/1970s about whether lengthy prior experience in Washington, DC appears to be an advantage or a disadvantage in presidential elections. Although Melman does not make this point, the shift corresponds to the same period in which we shifted from the convention system to the primary-election dominated system for choosing party nominees.

Notice that from 1920-1964, the only winning candidate with no prior DC experience was Dwight Eisenhower, who of course was the Supreme Allied Commander for WWII. Since the shift to primary elections, we’ve elected five presidents with no prior DC experience: Carter, Reagan, Clinton, G.W. Bush, and Trump.

Correlation does not prove causation, of course. But I continue to believe the shift to primary elections for choosing the parties’ nominees is one of the most dramatic, yet underappreciated, changes we’ve made to our democratic processes in the last 50 or so years.