Rick Santorum is the Republican senator from Pennsylvania and chairman of the Senate Republican Conference. I made a decision recently to support my colleague, Senator Arlen Specter—a pro-choice Republican—in the Pennsylvania Senate primary race. While the decision was controversial with some, I’m convinced it was the right one. Put simply, I supported Senator Specter because it will further the causes in which I believe and because it’s in the best interest of my state. Politically, Senator Specter is a very strong general-election candidate with a high likelihood to win the seat, while his opponent, pro-life Congressman Pat Toomey, would have...