Hillary Clinton will finally be facing questions from members of Congress on Wednesday about the deadly terror attack on the U.S. diplomatic mission in Benghazi, Libya.

Lawmakers have long wanted Clinton's full accounting of the September 11 assault that killed Ambassador Christopher Stevens and three other Americans.

Republican Sen. John McCain wants a full explanation of Clinton's understanding of the attack -- what happened before, during and after.

The 2008 GOP presidential nominee and the top Republican member of the Senate Armed Services Committee, McCain told CNN this week that he feels "the American people were clearly deceived."

McCain told reporters eight days after the attack that he had information the State Department had been warned.