A rally was held in Pittsburgh Thursday in support of Summer Lee, a Democratic candidate for the 12th Congressional District.One of her supporters, Vermont Sen. Bernie Sanders, joined Lee for the rally. Sanders announced last week he was endorsing Lee. "We have a working class, a middle class, in this country who are struggling and it's absolutely imperative we get (people) into congress who are prepared to stand up and take on powerful special interest and fight for working families," Sanders told Pittsburgh's Action News 4. "Summer is one of those people who will do that."Pittsburgh's Action News 4 spoke exclusively with Senator Sanders to discuss the upcoming election. Watch the interview in the video player above. "I've known Summer for a number of years and Summer believes as I do, that it is totally absurd that you have billionaires in this country, some of the very richest people paying nothing, not a penny in federal income tax," Sanders said. "(All) because you have a rigged tax system that favors the wealthy and large corporations.""We're seeing right now how working families, working class people are being hit, we see it at the gas pump, we see it in our groceries, in our rent," Lee said. "We're not seeing a corresponding urgency coming from government to solve those problems and address them."Pittsburgh Mayor Ed Gainey was also in attendance to support Lee. "When I look in their eyes and they see diversity, not as a word that sounds pretty but a word that say 'we are one America, we are one people, we are one humanity," Gainey said. Both Gainey and Sanders expressed frustration with the attack ads on Lee circulating the web."I am appalled by the kind of Super Pac billionaire money that is flooding not only in Pennsylvania, but all across this country against candidates who stand for working families," Sanders told Pittsburgh's Action News 4. "I think it's really shameful and I really believe that politics should be better than that, especially in the democratic primary," Lee said, commenting on the attack ads. "This is a movement that we've been creating where we have lifted up a positive message, we've lifted people up and centered the needs and our values and visions. I wish that all campaigns did that."The rally was held at The Westin Pittsburgh hotel. Lee is running for the 12th district, which is a newly drawn district that includes parts of Allegheny and Westmoreland County, to replace U.S. Rep. Mike Doyle who is not seeking reelection. The four other candidates looking to replace Doyle on the Democratic ticket are Jerry Dickinson, Steve Irwin, Will Parker and Jeff Woodard. The primary election will happen Tuesday, May 17.