Arlen Specter, the former senator from Pennsylvania who stunned both parties on Capitol Hill in 2009 when he announced he would switch his party allegiance to Democrat after 42 years as a Republican, has died. He was 82.
Specter died at his Philadelphia home from complications of non-Hodgkin's lymphoma.
Specter's battle with cancer has been long. In addition to the removal of a brain tumor, he was diagnosed and underwent chemotherapy for Hodgkin's disease in 2005, only to undergo treatment again when it resurfaced in 2008.
He published a book, "Never Give In: Battling Cancer in the Senate," about dealing with the disease after his initial diagnosis.
PHOTOS: Arlen Specter Through the Years
President Obama said Specter was "always a fighter."
"From his days stamping out corruption as a prosecutor in Philadelphia to his three decades of service in the Senate, Arlen was fiercely independent – never putting party or ideology ahead of the people he was chosen to serve. He brought that same toughness and determination to his personal struggles, using his own story to inspire others," Obama said in a statement.
In August, Specter announced he was "battling cancer" again -- this time with non-Hodgkin's lymphoma.
"I'm battling cancer. It's another battle I intend to win. I'm grateful for all the well wishes I've received. I'm looking forward to getting back to work, to the comedy stage, to the squash court and to the ballpark," Specter said in a statement released through his Philadelphia office, The Associated Press reported.
Last month, he was released from a Philadelphia hospital.
He is survived by his wife, Joan, and two sons, Shanin and Stephen.
Born in Witchita, Kansas, in 1930, Specter was the youngest son of Lillie and Harry Specter, a Ukrainian immigrant. While in college, Specter said the Jewish family uprooted from Kansas and moved to Philadelphia when his sister came of age so she could find eligible bachelors of their faith.
After serving stateside with the Air Force during the Korean War, Specter returned to college to pursue a law degree at Yale.
He was admitted to the Pennsylvania bar in 1956 and served as assistant district attorney of Philadelphia from 1959 to 1964.
Specter began his political career when he was appointed assistant counsel to the Warren Commission, the congressional body tasked with investigating the assassination of President John F. Kennedy. Recruited at the recommendation of then-Rep. Gerald Ford, Specter became one of the original proponents of the "single bullet" theory.
Specter wrote about that experience in his book, "Passion for Truth: From Finding JFK's Single Bullet to Questioning Anita Hill to Impeaching Clinton," which was published in 2000.
In 1965, Specter was elected district attorney of Philadelphia, where he served two terms until his defeat in 1973. After failed bids for congress and the Pennsylvania governor's office, he eventually was elected to the Senate in 1981.
Specter's Political Career
In his three decades -- five terms -- in the Senate, Specter was a formidable presence on Capitol Hill, chairing three committees during his Senate career: the Intelligence, Judiciary, and Veterans Affairs committees.
Specter participated in 14 Supreme Court confirmation hearings and took leadership roles on legislation including the Armed Career Criminal Act, the Terrorist Prosecution Act, the Hate Crimes Act and legislation to expand Veteran's Rights, legislation to reform asbestos litigation, legislation for education and worker safety and the bill that created the Inspector General of the CIA.
In October 2002, Specter voted for authorizing the Iraq war.