Sen. Lindsey Graham (R-S.C.) has upped his already harsh rhetoric against outgoing Secretary of State Hillary Clinton, claiming that she "got away with murder" in the Benghazi, Libya, attack that killed Ambassador Chris Stevens and three other Americans.

"I haven't forgotten about Benghazi. Hillary Clinton got away with murder, in my view," Graham said on Fox News Monday evening, speaking to Greta Van Susteren. "She said they had a clear-eyed view of the threats. How could you have a clear-eyed view of the threats in Benghazi when you didn't know about the ambassador's cable coming back from Libya?"

He also threatened to block the nomination of former Sen. Chuck Hagel (R-Neb.) as President Barack Obama's next secretary of defense until outgoing Defense Secretary Leon Panetta testifies about the attack.

Graham was part of a cadre of GOP senators who loudly protested the possible nomination of United Nations Ambassador Susan Rice as secretary of state over comments she made four days after the Benghazi attack, reflecting the then intelligence assessment of the incident as linked to an anti-Islam video. Rice withdrew from consideration under their criticism.

Clinton appeared in front of the Senate Foreign Relations Committee last Wednesday to answer questions about the attack. Exasperated by a similar what-did-you-know-when line of questioning from Sen. Ron Johnson (R-Wis.), she said, "With all due respect, the fact is we had four dead Americans. Was it because of a protest, or was it because of guys out for a walk one night who decided they'd go kill some Americans? What difference at this point does it make?"

Also on HuffPost:

Loading Slideshow...
  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on Capitol Hill January 23, 2013 in Washington, D.C. (Photo by Chip Somodevilla/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on Capitol Hill January 23, 2013 in Washington, D.C. (Photo by Alex Wong/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on Capitol Hill January 23, 2013 in Washington, D.C. (Photo by Chip Somodevilla/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on Capitol Hill January 23, 2013 in Washington, D.C. (Photo by Chip Somodevilla/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on Capitol Hill January 23, 2013 in Washington, D.C. (Photo by Alex Wong/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on Capitol Hill January 23, 2013 in Washington, D.C. (Photo by Alex Wong/Getty Images)

  • U.S. Secretary of State Hillary Clinton arrives to testify before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, DC, on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton arrives to testify before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya in the Hart Senate Office Building on January 23, 2013 on Capitol Hill in Washington, D.C. (MANDEL NGAN/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya, during a hearing on Capitol Hill in Washington, D.C., on January 23, 2013. (SAUL LOEB/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the Senate Foreign Relations Committee about the September 11 attacks against the U.S. mission in Benghazi, Libya, on Capitol Hill January 23, 2013 in Washington, D.C. (Photo by Alex Wong/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the House Foreign Affairs Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya in the Rayburn House Office Building on January 23, 2013 in Washington, D.C. (MANDEL NGAN/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the House Foreign Affairs Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya in the Rayburn House Office Building on January 23, 2013 in Washington, D.C. (MANDEL NGAN/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the House Foreign Affairs Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya in the Rayburn House Office Building on January 23, 2013 in Washington, D.C. (MANDEL NGAN/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton is seated before testifying before the House Foreign Affairs Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya in the Rayburn House Office Building on January 23, 2013 in Washington, D.C. (MANDEL NGAN/AFP/Getty Images)

  • U.S. Secretary of State Hillary Clinton testifies before the House Foreign Affairs Committee on the September 11, 2012 attack on the U.S. mission in Benghazi, Libya in the Rayburn House Office Building on January 23, 2013 in Washington, D.C. (MANDEL NGAN/AFP/Getty Images)