Former Pennsylvania Senator Arlen Specter is battling cancer for the third time and has been hospitalized. 

"I'm battling cancer. It's another battle I intend to win," Specter said in a statement on Tuesday. "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 had breathing difficulties two months ago, and doctors found a tumor by his lung.

Specter was first elected in 1980 and best known as a moderate Republican senator from Pennsylvania. In 2009, he switched parties when it became obvious he could not beat Pat Toomey in the primary. Spector's move gave Democrats 60 votes in the Senate, making it filibuster-proof. 

Endorsed by President Barack Obama and former Pennsylvania Gov. Ed Rendell, he lost the Democratic primary to Joe Sestak. During that campaign, Sestak accused the Obama administration of offering him a job in the administration in exchange for dropping out of the race. It was alleged that Rahm Emmanuel, who was the White House Chief of Staff, sent Bill Clinton to meet with Sestak to illegally offer him a job in the administration. Sestak refused the offer en route to his primary victory over Specter. 

Specter first made a name for himself in politics after John F. Kennedy’s assassination. He was a part of the commission that advanced the “single bullet theory” which suggested Kennedy’s wounds were caused by one bullet.