
Click through to see highlights from U.S. Sen. Lindsey Graham's political career:

Graham; Sir Elton John, center; and filmmaker and John's husband, David Furnish, pose after testimony at a U.S. Senate hearing on the global fight against AIDS on May 6, 2015. Graham and Democratic Sen. Patrick J. Leahy of Vermont hosted John as part of their bipartisan effort to combat HIV infection.

Graham rushes to the Senate chamber to vote on an attempt to override U.S. President Barack Obama's veto of the Keystone XL Pipeline legislation March 4, 2015. Graham was elected to the U.S. Senate in 2002 and was re-elected in 2008 and 2014.

Graham listens to testimony during a Senate Armed Services Committee meeting on national security strategy on January 27, 2015. According to his website, Graham continues to serve his country in the U.S. Air Force Reserves as a senior individual mobilization augmentee to the judge advocate general.

Graham arrives for a closed briefing of the Armed Services Committee on July 30, 2014. Before serving in the Senate, Graham was elected to the U.S. House of Representatives in 1994.

Graham talks to U.S. Sen. Marco Rubio, R-Florida, before a news conference on Capitol Hill on July 24, 2014.

Graham and U.S. Sen. Ted Cruz, R-Texas, right, listen as President Barack Obama delivers the State of the Union address on January 28, 2014. Graham was in the U.S. Air Force and logged six-and-a-half years of service on active duty as an Air Force lawyer.

Graham holds a news conference on Benghazi, Libya, at the U.S. Capitol on October 30, 2013. From left, he is flanked by Sen. John McCain, R-Arizona; Rep. Jason Chaffetz, R-Utah; and Rep. Jim Jordan, R-Ohio. Graham has been an outspoken critic of how the Obama administration has handled the September 11, 2012, attack on the U.S. diplomatic, in which four U.S. citizens died.

Israeli Prime Minister Benjamin Netanyahu, center, meets with U.S. Sen. John McCain, R-Arizona, and Graham on June 30, 2013, in Jerusalem.

McCain, left, and Graham speak during a news conference about Benghazi on February 14, 2013, on Capitol Hill.

Graham talks with reporters before heading into the Senate Republican Caucus policy luncheon at the U.S. Capitol May 8, 2012.

Graham speaks to reporters after a news conference about his Social Security reform plan at the U.S. Capitol on April 13, 2011.

Graham, left, and McCain call on participants during a health care town hall meeting on September 14, 2009 at the Citadel in Charleston, South Carolina. According to his website, Graham is a native South Carolinian and grew up in a blue collar family in the small town of Central, where his parents ran a restaurant and pool hall.

U.S. President George W. Bush, left, stands with Graham on the steps of Air Force One at the airport in Greenville, South Carolina, in March 2002.