"Speaking is hard for me," the former congresswoman said on stage at Iowa State University. "But January, come January, I want to say these two words: Madame President."
Giffords, who was shot in the head five years ago during a shooting in Arizona, endorsed Clinton earlier this month citing gun control as the key issue. Today was her first public campaign event with the Democratic presidential candidate.
"Hillary is tough. Hillary is courageous," Giffords told the crowd of roughly 1,100. "In the White House she will stand up to the gun lobby. That's why I'm voting for Hillary."
Seated behind Giffords was her husband, former astronaut Mark Kelly, as well as both Hillary and Chelsea Clinton, who is joining her mother on the campaign trail today.
When Hillary Clinton took the stage, she hugged Giffords, and then thanked her and Kelly for their "courage" and "sense of mission" as she vowed to take on the gun lobby as president.
"I really agree so much with them. That it is time, my friends, to stand up for common sense gun safety measures, to stand up against the gun lobby. And to turn that into a voting issue," Clinton said.
Here voice growing louder, she added: "What is wrong with us? How can we continue to ignore the toll that this is taking on our children and our country?"
Giffords is one of many high-profile supporters to join Clinton on the campaign trail in this final push before the Iowa caucuses. Planned Parenthood president Cecile Richards, New Jersey Sen. Cory Booker, and of course, Bill Clinton have been campaigned with her too.