Breaking down the CNN National Security Debate: Who stood out, who stumbled?

GOP presidential debate number 11 has come and gone. The CNN National Security Debate last night was held just steps from the White House, and each candidate argued that they could be doing a better job than President Obama.

So who stood out? Who stumbled? And will this moment prove to be a game changer? Carol Costello speaks with Republican Strategist Karen Hanerty and CNN contributor David Frum to get their take.