KUSA - Tom Sullivan would forgive you for thinking of him as the “theater shooting dad” running for state senate -- it’s just not how he identifies himself.

“It is a part of who I am,” Sullivan told 9NEWS. “I won’t allow it to define me.”

That’s not to say the loss of his son Alex didn’t lead him to this point.

When Tom’s son Alex Sullivan and 11 others died in a hail of gunfire at the Century 16 theater in Aurora back in 2012, the father got involved in politics.

Tom Sullivan was one of several relatives of the deceased who worked to change laws, lobbying for new state gun controls that passed in the 2013 legislative session.

A 59-year-old Democrat, Tom Sullivan hopes to build off that experience and work on a wider array of issues as a state legislator. He can only guess what Alex would think of his foray into politics.

“I would hope he would be proud of his dad,” Sullivan said with a tremble in his voice. “He’d probably be scared, probably, ‘What are you getting yourself into?’”

Sullivan said he would like his late son to know that “he’s helped to give me a voice to affect some change out here.”

The longtime postal worker and Air Force veteran lives in Centennial with his wife Terry.

He’s aiming for state senate district 27, held by incumbent Republican Sen. Jack Tate (R-Centennial.)

“I welcome Mr. Sullivan to the race and I look forward to seeing him out on the campaign trail,” Tate said. (R-Centennial). “I’ll continue championing the concerns of my constituents.”

On paper, it’s a steep, uphill battle. Not only is there an incumbent, but the district is safely Republican.

GOP voters outnumber Democrats by roughly 9,000 voters in the district, making up 38 and 28 percent of the active voter rolls respectively.

Tate is focused in on “conservative stewardship” of state money and local control of education, while Sullivan’s early messaging is focused around “working families” and building community.

Sullivan can point to at least one issue on which he would buck the Democratic party. He recently testified in favor of a bill from conservative Sen. Kevin Lundberg (R-Berthoud,) which would have made it easier for juries to impose the death penalty.

He told theater shooting prosecutor George Brauchler that he’s one of “his top five favorite Republicans: the first two are my mom and dad.”