Arlen Specter was an American politician who served as a U.S. Senator from Pennsylvania for 30 years, from 1981 to 2011. He was a member of the Republican Party for most of his career but switched to the Democratic Party in 2009. Specter was known for his moderate views and played a significant role in various legislative issues, including judicial nominations and health care. Born on February 12, 1930, Specter was also a lawyer and served as the District Attorney of Philadelphia before his Senate career. He was involved in high-profile investigations, including the Warren Commission that examined the assassination of John F. Kennedy. Specter passed away on October 14, 2012.