Vargas and former state Sen. Denise Ducheny, both vying to fill Rep. Bob Filner's 51st Congressional District seat, were scheduled to face off in an April 20 debate with ABC10 cameras rolling.The debate was canceled, leaving only frustration and excuses as to why it did not happen."It's an unfortunate pattern that Mr. Vargas has set over many years," said Ducheny.Ducheny told 10News she believes this is a pattern."[Last two] times he ran against Congressman Filner, he refused to debate him," Ducheny added."I think it was a wise move quite honestly," said local political analyst John Dadian.Dadian told 10News while it's bad for the constituents, it's a smart campaign move."When you are the frontrunner, what you want to do is you want to play it safe, don't take any risk," added Dadian.The 51st Congressional District stretches from the South Bay all the way into the Imperial County, with more than 235,000 voters. The majority of the voters are in San Diego County."My understanding of the Senator's position is that he is more than happy to participate in debates when all the candidates are invited," said Vargas' political consultant Larry Remer.Remer added that Vargas did not want to participate since it was only to include himself and Ducheny. He wanted the debate to include all seven candidates.In a 10News scientific poll of 500 voters, 90 percent of voters said they were familiar with Vargas, while 64 percent of those same voters were familiar with Ducheny. Fifty percent or less, were familiar with the other candidates.10News invited the top two candidates based on those results."History is replete with examples of people nobody ever heard of bursting through, ending up ahead of the pack," added Remer.Critics say Vargas is trying to control the format so he doesn't have to appear much on camera and won't have to answer many questions.Vargas also backed out of a debate at KPBS last month.The question is whether appearing to duck debates could hurt the popularity he's trying to protect.So far, Vargas and Ducheny are the most financially viable candidates. Vargas has raised more than $469,000, while Ducheny has raised more than $216,000.None of the other five candidates show contributions over $500.