How did Cook County Commissioner Mike Quigley win Tuesday’s Democratic primary in Illinois’ 5th District Congressional race? His direct mail guru Pete Giangreco tells Campaign Insider that it’s a victory of mailers and smart messaging.

Quigley won Tuesday with just over 22 percent of the vote—less than 12,000 actual votes in the crowded field. Despite being outspent and outgunned on the airwaves by two better funded challengers, Quigley won by a four point margin.

“We out-communicated everyone when it came to mail,” says Giangreco, partner at The Strategy Group. Giangreco was one of President Obama’s top campaign strategists in 2006 and 2008. He also did direct mail for John Edwards’ 2004 presidential campaign. “While [our opponents] were husbanding their resources for TV, we had already dropped seven or eight pieces of mail.”

Quigley’s main opponents—State Reps. Sara Feigenholtz and John Fritchey—were up on the airwaves before Quigley. Feigenholtz ran three ads total, while Fritchey ran two. Quigley went up with his first and only ad in the last week of the campaign.

“We were tapping into voter anger with our message,” says Giangreco. Several of the campaign’s mailers focused attention on Quigley’s political foil—Todd Stroger, president of the Cook County Board of Commissioners. As board members, the two men battled often, with Stroger being seen as part of the “old guard” of Chicago politicians.

“We knew we didn’t have the money to run this thing on TV,” Ginagreco says. “So we ran the race more like a County Commissioner or state Senate race.”

Shane D'Aprile is senior editor at Politics magazine.