"I could not be more excited to have my friends Gabby Giffords and Mark Kelly come to Iowa for Bruce, Blues, and BBQ," Braley says in a statement. "Gabby and Mark have made it their life's mission to bring people together and find common sense solutions that solve some of the tough problems facing our country. I work hard every day to live by their example, and I hope to bring that same spirit to the US Senate."

Braley is all but certain to be the Democratic nominee for retiring Sen. Tom HarkinTom HarkinThe Hill's 12:30 Report Distance education: Tumultuous today and yesterday Grassley challenger no stranger to defying odds MORE's (D-Iowa) seat. The GOP has yet to settle on a candidate in the swing state; all of the state's high-profile Republicans passed on the race, and there are a number of lesser-known Republicans running for the seat, allowing Braley to build up a big war chest for the general election.