Question: What is the name of this American lawyer and politician who served as United States Senator from Pennsylvania, who surpassed Boies Penrose's record for the longest serving senator?
Context: Penrose Peak is a mountain in the Bighorn Mountains of the Rocky Mountains in Wyoming, United States.  Like Mount Penrose in British Columbia, Canada, it was named for Senator Boies Penrose of Pennsylvania, who was an avid outdoorsman and went on hunting expeditions in this area. Boies Penrose (November 1, 1860 – December 31, 1921) was an American lawyer and Republican politician from Philadelphia, Pennsylvania.  He represented Pennsylvania in the United States Senate from 1897 until his death in 1921.  Penrose was the fourth boss of the Pennsylvania Republican machine, following Simon Cameron, Donald Cameron, and Matthew Quay.  Penrose was the longest-serving Pennsylvania Senator until Arlen Specter surpassed his record in 2005. William Thad Cochran (born December 7, 1937) is an American Republican politician.  He is the current senior United States Senator from Mississippi (the third most-senior Senator and the second most-senior Republican member), first elected to the Senate in 1978, and the Chairman of the Senate Appropriations Committee, which he had also chaired from 2005 to 2007.  He also chaired the Senate Agriculture Committee from 2003 to 2005.  Cochran won reelection to a seventh term in 2014, after defeating Chris McDaniel in an intense primary run-off election.  He is currently the dean of the Mississippi congressional delegation.  He is also on track to become the longest serving Republican Member of Congress if he serves until 2019, surpassing Joseph Gurney Cannon, former Speaker of the House, who served for 46 years. This is a complete list of United States Senators from Kentucky.  Its senators belong to Classes 2 and 3.  Kentucky is currently represented in the U.S. Senate by Republicans Rand Paul and Mitch McConnell.  Currently on his sixth term in office, McConnell is currently Kentucky's longest serving Senator and has also been the Republican Leader of the United States Senate since 2007. Donald Lee Nickles (born December 6, 1948) is an American politician and lobbyist who was a Republican United States Senator from Oklahoma from 1981 until 2005.  He was considered both a fiscal and social conservative.  After retiring from the Senate as the longest serving senator from Oklahoma, he founded the Nickles Group, a lobbying firm. Arlen Specter (February 12, 1930 – October 14, 2012) was an American lawyer and politician who served as United States Senator from Pennsylvania.  Specter was a Democrat from 1951 to 1965, then a Republican from 1965 until 2009, when he switched back to the Democratic Party.  First elected in 1980, he represented his state in the Senate for 30 years. Kay Bailey Hutchison (born Kathryn Ann Bailey; July 22, 1943) is an American lawyer, businesswoman, politician, and diplomat who is currently serving as the 22nd United States Permanent Representative to NATO.  She served as a United States Senator from Texas from 1993 to 2013.  She is a member of the Republican Party.  Texas's first female U.S. Senator, Hutchison also became the first Texas U.S. Senator to receive more than four million votes in a single election. Charles Bingham Penrose (February 1, 1862 – February 28, 1925) was an American gynecologist who invented the surgical drain known as the Penrose drain.  Born in Philadelphia, Penrose was the son of a medical school professor and his brothers included Pennsylvania state senator Boies Penrose and geologist Spencer Penrose.  The grandson of prominent politician Charles B. Penrose, he married into the wealthy Drexel family of the same city.  Penrose was an early advocate for the use of drainage tubes in abdominal surgery. Theodore Fulton "Ted" Stevens Sr. (November 18, 1923 – August 9, 2010) was a United States Senator from Alaska, whose tenure extended from December 24, 1968, until January 3, 2009.  He was thus the longest serving Republican senator in history at the time he left office; his record was surpassed in January 2017 by Orrin Hatch of Utah.  He was President pro tempore in the 108th and 109th Congresses from January 3, 2003, to January 3, 2007, and the third senator to hold the title of President pro tempore emeritus. Duncan Upshaw Fletcher (January 6, 1859June 17, 1936) was an American lawyer and politician of the Democratic Party.  Senator Fletcher was the longest serving U.S. Senator in Florida's history.
Answer: Arlen Specter