For all the advice she had received about not looking too imperious and arrogant, at times Hillary Clinton could barely hide her disgust at having to defend her record as U.S. Secretary of State from such a miserable bunch of accusers.

On Thursday, in the most hotly anticipated Washington showdown for years, she was grilled for 11 hours by a Republican-dominated congressional committee investigating the 2012 killings by Islamic extremists of the U.S. ambassador and three other Americans in Benghazi, Libya.

Millions of U.S. TV viewers watched agog. It wasn't so much the answers to the tragedy they were interested in, although those are serious enough as Mrs Clinton is accused of failing to protect the four victims on her watch.

No, the real attention was focused on how Queen Hillary would respond to being hectored by a bunch of Republicans slavering to score political points and damage her standing in the polls.