Facing Primary Battle, Specter Shifts Leftward

Since going blue, Arlen Specter voted with Democrats some two-thirds of the time on “Contentious Votes”—defined by Nate Silver of FiveThirtyEight.com as “anything that comes up for a floor vote and where the majority of each party splits their votes.” That is, up until Rep. Joe Sestak announced a primary challenge to the Pennsylvania senator May 27. Since then, Specter has voted with his new party 97% of the time.

“The real question is how Specter will behave if and when he wins the primary challenge, and the pressure from the left is off,” writes Silver. He “appears to be just as capable of reacting to pressure from his right as to his left.” In the first part of the year, the still-Republican Specter voted with Democrats some 58% of the time; then after a poll showed him 14 points behind GOP challenger Pat Toomey, he voted with Dems only 16% of the time.