Cory Booker Surprised by Anti-Buttigieg Super PAC Attack Ad That Features Himself During CNN Interview

New Jersey Senator Cory Booker admitted on CNN he was "caught off guard" by a Super PAC attack ad targeting South Bend, Indiana Mayor Pete Buttigieg, played during his live appearance Friday.

Booker, who has previously disavowed accepting PAC money, briefly appeared shocked after CNN host Jim Acosta played a campaign ad that compared the former mayor of Newark, New Jersey to fellow Democratic presidential candidate, Pete Buttigieg. The ad is set to air in Des Moines and Cedar Rapids, Iowa, just days after a pro-Booker PAC shut down due to lack of fundraising and Acosta pressed Booker on the anti-Buttigieg attack ad. Booker said he was unconcerned about polls because Democrats leading one year before an election never win the presidential nomination.

The United We Win PAC ad begins by showing pictures of Buttigieg before a narrator says, "He's a Rhodes Scholar, a successful mayor, a uniter...no, not that guy, it's Cory Booker."

"Are you running against that guy, senator?" Acosta asked Booker.

"God. You know what's so funny is I didn't even know that was out and this is the first time I'm seeing it so you caught me a little bit off guard," Booker told the chuckling CNN host.

Booker studied abroad at the University of Oxford on a Rhodes Scholarship before attending Yale Law School in the early 1990s. He won his first political upset victory in 1998 on the Municipal Council of Newark. He went on to win the 2002 Newark mayoral election and became a U.S. senator in 2013. Buttigieg also was a Rhodes a Scholar after graduating from Harvard University.

"Look, at the end of the day, I'm running for the soul of our country," Booker continued. "I'm running because I believe this nation should not be attacking each other, we should not be tearing each other down. This is a time we should be building each other up. And if anybody has followed my campaign from the start, we've been the one saying we need to be a Democratic party that can unify and come together, so I celebrate the people that are in the race and my campaign is not about tearing anybody down."

Acosta asked Booker why Buttigieg has been doing so well in Iowa polls while his campaign has seemingly struggled in the polls since he announced his run.

"Look, I'll leave that to the pundits but we know this: the way people are measuring 'back of the pack, front of the pack' is with polling. And never in your lifetime or mine has there ever been someone who has gone, at this point in the November, from leading in the polls, to the White House from the Democratic Party."

Booker then went on to compare himself to another former Rhodes Scholar, Bill Clinton, as well as several other past successful Democratic nominees from recent decades.

"So my campaign looks a lot more like Bill Clinton's did, Jimmy Carter's did, even Barack Obama," Booker said. "The first two were polling at single digits at this point, Barack Obama was 21 points behind Hillary Clinton. What's making the difference for us, where we're seeing this post-debate surge is in fundraising, and matter of fact, we're number three in net favorability."

"Did that attack ad make you feel uncomfortable? Going after Pete Buttigieg like that?" Acosta pressed.

"Again, I only saw the clip you had, I don't know if it was done tongue-in-cheek or funny. I just have a philosophy which is I will do nothing to tear down the character of anybody in this race."