HARRISBURG, Pa. – For most of his 30 years as Pennsylvania’s longest-serving U.S. senator and prominent moderate in Congress, Arlen Specter was a Republican, though often at odds with the GOP leadership.

He helped end the Supreme Court hopes of former federal appeals Judge Robert H. Bork, who was nominated by President Ronald Reagan. Decades later, he was one of only three Republicans in Congress to vote for President Barack Obama’s economic stimulus.

His breaks with his party were hardly a surprise: He had begun his political career as a Democrat and ended it as one, too.