In an ad for San Diego City Councilman Carl DeMaio's campaign, DeMaio calls himself an independent, causing some to raise their eyebrows.The ad says, "For Carl DeMaio, independence is not a label, it's his life story."The ad goes to tout the Republican's ability to bring people together, saying, "Carl DeMaio has always been an independent voice, a problem solver."Because of DeMaio's party status, his opponent, Democrat Rep. Bob Filner, takes issue with the use of the word "independent.""I have heard Mr. DeMaio over the last few weeks try to reinvent himself as somehow a man of the people, and I want to make it clear -- he's a man of the special interests," said Filner.A recent 10News poll showed Filner leading DeMaio by six points, with 12 percent of voters still undecided.Political science professor Carl Luna said DeMaio is trying to appeal to those undecided voters with his new ad."The only way to grow that base in a city that's rapidly becoming purple, with Democratic registration up, is to appeal to moderates in the middle," said Luna.Filner's campaign has also unveiled their own ads.The two candidates will meet in several more debates from now until Election Day.