Arlen Specter, Pennsylvania Senator, Is Dead at 82

WASHINGTON — Arlen Specter, the irascible senator from Pennsylvania who was at the center of many of the Senate’s most divisive legal battles — from the Supreme Court nominations of Robert H. Bork and Clarence Thomas to the impeachment of President Bill Clinton — only to lose his seat in 2010 after quitting the Republican Party to become a Democrat, died Sunday morning at his home in Philadelphia. He was 82.

The cause was complications of non-Hodgkin’s lymphoma, his son Shanin said. Mr. Specter had previously fought Hodgkin’s disease and survived a brain tumor and heart bypass surgery.

Hard-edged and tenacious yet ever the centrist, Mr. Specter was a part of American public life for more than four decades. As an ambitious young lawyer for the Warren Commission, he took credit for originating the theory that a single bullet, fired by a lone gunman, struck both President John F. Kennedy and Gov. John B. Connally of Texas. Seconds later, Kennedy was struck by a fatal shot to the head from the same gunman, the commission found....