Republican Senators Rand Paul (Ky.) and John McCain (Ariz.) look to be Hillary Clinton's biggest inquisitors in the Wednesday Benghazi meetings. 

Rand Paul has promised to grill Clinton over the attack ... what he called "a career-ending" mistake. Paul and the GOP appear to have legitimate reasons for pressing Secretary Clinton — including evident oversight on security for the Benghazi mission.

On a recent trip to Israel, Paul told Business Insider: "I think she has to accept responsibility for Benghazi … That's the problem with government — government is anonymous and so no one is accountable. The reason you want somebody to be accountable is that you don't want someone to make that decision again." 

"She needs to be held accountable for it, and I think she needs to answer questions for it," Paul said.

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."

"The American people have received nothing but contradictory statements from all levels of our government," McCain said.