Arianna, Giuliani Spar Over His Record, Bernie Kerik, Support For Marco Rubio (VIDEO)

Arianna sparred with Rudy Giuliani on MSNBC's "Morning Joe" today over his endorsement of Tea Party favorite Marco Rubio over Charlie Crist in Florida's Republican Senate primary. Arianna noted that Giuliani's judgment in people "has not been stellar," a relevant factor when people are considering how much weight to give his endorsement of Rubio.

There's all this talk, that we've just heard from the mayor [Giuliani], about the takeover of government by Obama and his administration, which is so over the top, with the greatest respect, Mr. Mayor. And also, your judgment in people has not been stellar -- Bernard Kerik, anybody? So the fact that you're supporting Rubio now, I don't know exactly how seriously we should take it.

Kerik was one of Giuliani's closest allies, who went from being the mayor's bodyguard to New York's police commissioner. He later took a lucrative position at Giuliani Partners, leaving to take a job training the Iraqi police force soon after the U.S. invasion. He failed miserably. Despite this failure (the former commander of U.S. forces in Iraq called Kerik's tenure "a waste of time and effort"), Giuliani successfully lobbied the Bush administration to nominate Kerik as Director of Homeland Security. Kerik ultimately withdrew his nomination, unable to survive the vetting process. He was recently sentenced to four years in prison after pleading guilty to eight felonies charges, including tax fraud and lying to White House officials.

Giuliani defended himself by touting his record of cleaning up New York City as mayor, and saying that Kerik was just a small part of his overall reputation. Arianna responded:

That's not either/or. You are not judging the mayor's entire history. We're talking about something very important, something very specific. And we're talking also about this knee-jerk attempt to criticize the administration on everything, especially the position of the president on terrorism from a man who said you don't know if waterboarding is torture. I don't know if you still hold that position.

WATCH: (clip below, full segment underneath)