Jennifer Eckstrom introduced Richard Carmona, who recalled his life growing up poor and dropping out of high school, remarking "My mom would never have predicted this."
"When I look back on my life I always look back at how lucky I am," he said.
Carmona credited the U.S. Army with saving his life and giving him direction, because he was able to use his GI Bill benefits to go to college.
Carmona, who most likely faces Republican Jeff Flake in the general election, talked about passing the DREAM Act and helping returning US veteran find jobs.
"I'm running because, like you, I am fed up and I want to solve some problems," he said. "Put me back to in active duty because I am ready to work for you and this state."
Pima County Chair Jeff Rogers introduced former U.S. Senator Dennis DeConcini as "the last to really represent the values of this state."
DeConcini urged the crowd to get behind Carmona campaign and took time to recall the past — "First of all, right here," he said, touching his chest, "from my corazon to you."
"You have a great opportunity to do something for Arizona," he said, recalling the party's ability to run grassroots campaigns and organizing.