Our colleague David Fahrenthold traveled to Milwaukee to get the dish on why Gov. Scott Walker left college before graduating. The simplest answer is Walker’s own: He got a job — though whether there is more to that story remains unclear.

What is clear is that if Walker ascended to the White House — he’s holding his own in most GOP primary polls — he’d be the first president in more than 60 years without at least a bachelor’s degree. Of America’s 44 presidents, just 11 didn’t graduate from college.

Moreover, only one was from the 20th century, Harry Truman — who withdrew from Spalding’s Commercial College in Missouri — and he was first elected as an incumbent having taken over the job after Franklin D. Roosevelt’s death. The last to be elected outright was William McKinley in 1897. He dropped out of Allegheny College in Pennsylvania after one year.

H.W. Brands, a presidential historian at the University of Texas, said unless you’re someone like Bill Gates or Steve Jobs (both college dropouts), not having a college degree would be “a serious handicap” in running for president.

“Nowadays a college degree has become the entry credential to nearly all jobs requiring any skill at all. A candidate lacking one would have some heavy explaining to do,” he said.

The other former presidents without a college diploma include: George Washington, Andrew Jackson, Martin Van Buren, William Henry Harrison, Zachary Taylor, Millard Fillmore, Abraham Lincoln, Andrew Johnson and Grover Cleveland.

Matt Dallek, a political science professor at George Washington University’s graduate school, said playing the outsider, ‘I’m just like you’ card has become more common in recent politics, but ultimately presidential candidates tend to be “a fairly privileged group of people.”

“Voters want some sense that our leaders are particularly gifted, smart, accomplished, extraordinary but at the same time ordinary,” Dallek said.

That said, Dallek does not believe pointing out Walker’s lack of a college degree would be a winning attack by his opponents.

There’s a fine line in higher education politics: don’t look down on voters who didn’t go to college, but maybe don’t take the Rick Santorum tack of calling people snobs who think students should go.

Douglas Brinkley, a historian at Rice University, agreed there is a balance to strike, but said Walker can use his lack of a degree as a strength, tapping into the many American voters who did not attend or finish college who may be attracted to Walker as a sort of blue collar hero. Truman was that person for a lot of people, Brinkley said, “the patron saint of the underdog.”

“You have to live by your biography,” he said. “It’s a way to identify with the working class — to mire himself in the Truman tradition.”