During the battle for the 2008 Democratic presidential nomination, Hillary Clinton made sure to let everyone know how much more experience she had than Barack Obama. “Ready to lead on day one,” she intoned. No one seemed to question her basic premise: More years of political experience would make for better leadership. But history says otherwise, according to University of Chicago political science doctoral candidate John Balz.

 

For the most part, political experience seems to have no bearing on a person’s ability to be a good, or even great, president. Balz looked for links between White House occupants’ resumés and how their tenures ranked in scholars’ assessments. Certain kinds of experience—serving in Congress, in particular—actually produced worse presidents. For every two years spent in Congress, a president’s ranking fell more than one spot. More often than not, former mayors made bad presidents, but since only three have served in the White House (Andrew Johnson, Grover Cleveland, and Calvin Coolidge), it’s impossible to know how strong the correlation is.

 

Experience as a governor, state-level legislator, state administrator, or general seems to be slightly beneficial, but the effect was too small to say for certain. (And the president with the most experience as a general, Zachary Taylor, was one of the nation’s worst chief executives.) Years spent in the private sector also raised presidents’ rankings a bit, a correlation perhaps boosted by one of the greatest there ever was: Abraham Lincoln, who had a long career as a private lawyer before he headed to Washington.

 

It’s impossible to flip the methodology around and try to predict whether a given set of experiences will produce a successful president. Divining how a president will fare based on his resumé is essentially a crapshoot. This is not to say some things aren’t predictable: Andrew Johnson’s resumé included 17 years of congressional service and three years as mayor of Greenville, Tennessee, a “perfect storm for lousy presidential performance.” Johnson was impeached by the House of Representatives in 1868.

 

The ability to steer the country on a path of greatness can’t be gained by time in the statehouse or on the floor of Congress. But candidates will campaign on their resumés nevertheless—in the end, it’s really all they have.