History on Corbett's side in Pa. gubernatorial

National pundits call Pennsylvania’s Republican Gov. Tom Corbett a “dead man walking” in the 2014 election cycle, citing his underwater approval ratings, lukewarm support from some in the GOP and a large Democratic field of challengers.

But the Democrats are swimming against deep historical currents, according a new analysis of the state’s voting patterns by Smart Politics, a numbers-crunching website from the University of Minnesota’s Humphrey School of Public Affairs.

It found that Pennsylvanians have voted against the sitting president’s political party in 18 of the last 19 gubernatorial races dating back to 1938.

The exception was Republican Gov. Dick Thornburgh, who clawed his way to a 2.7-percentage point victory in 1982, with Ronald Reagan in the White House.

Since 1860, Democrats have won only a single governor’s race when their own party held the White House, for a record of 1-16.

That’s a stronger streak than the famous “eight-year cycle,” in which the two parties have traded the governor’s office every eight years, going back to the post World War II era.