Ronald Reagan famously explained in 1962 that “I didn't leave the Democratic Party. The party left me.” Sen. Arlen Specter (D-PA) and Rep. Parker Griffith (R-AL) made similar statements when they hopped the aisle, but as primaries proved this month, their moves were less successful. Sean Trende noted back in December 2009 that party switchers have had a terrible track record in the last 30 years since they lack a base, and J-Mart had an interesting article today about how “primary voters seem intent on making up their own minds and creating a party in their own image.”
But if you look at the maps in Griffith and Specter’s respective home bases, it’s easy to see why they made the moves. Griffith’s northern Alabama district has never elected a Republican since it was created in 1876, and Specter’s base around Philly is historically loyal Republican (the first Republican National Convention was in Philly in 1856; and so was the one in 2000 that first nominated GWB).
The map below is not elections results. It is election shifts since 2000. If we were to go back another ten years, it’d be even more pronounced. The Griffith and Specter results are an indictment on party switchers, but it's also just a couple of cases of pols getting squeezed in generational political shifts.