A San Francisco supervisor's race is drawing huge amounts of independent spending. David Lee is running against incumbent Eric Mar in the Richmond neighborhood, the city's 1st District. According to the San Francisco Ethics Commission, independent groups have spent $319,000 on behalf of Lee’s campaign. That's about nine times what outside groups are spending to get Mar re-elected.

There is one particular attack ad on YouTube produced by the San Francisco Association of Realtors that's raising a lot of eyebrows. The three-minute video shows angry children -- their faces inexplicably smudged with black soot and dirt -- beating pots and pans and chanting for Eric Mar to be sent back to Mars. The demonstration is not real, and both Lee and Mar’s campaigns have reportedly called for the ad to be taken down. The Realtors Association did not return a request for comment.

Why would the Realtors Association spend $50,000 on this ad? Host Tara Siler talks with Corey Cook, political science professor at the University of San Francisco.