Rep. Lang Sias speaks after his introduction as Walker Stapleton's running mate at the Wings Over The Rockies Air Museum in Denver, July 11, 2018.

Nathaniel Minor/CPR News

Republican governor candidate Walker Stapleton now has a running mate. State Rep. Lang Sias, who currently represents Arvada in a seat he was first appointed to in 2015, is his choice for lieutenant governor on the GOP ticket.

A veteran, Sias served in combat as a U.S. Navy pilot and ground controller during Desert Storm and the Second Iraq War. His nearly three decade-long career includes a stint as an instructor in the storied Topgun program. Sias, 59, has also worked as an attorney for a technology law firm, and is now a pilot for FedEx.

"I learned in the air and on the ground in Iraq how important freedom is," Sias said during the news conference announcing he was joining the ticket. "And Walker Stapleton is going to keep Colorado free from congressman Jared Polis' Washington-style big government here in Colorado."

In politics, Sias has flashed an independent streak, swapping his party registration from unaffiliated to Democratic and back again before joining the Republican Party in 2007. He's only run for office as a Republican, losing a bid for Congress and two state senate elections before he was appointed to fill a state House vacancy in 2015. He subsequently won it in the 2016 election.

During the most recent legislative session, he sponsored bills related to consumer protection and to expand teacher residency programs. As a politician, he's considered a moderate. However, Democrats are likely to look deeper into his voting record to argue that he's further to the right.

The selection suggests the Republican ticket will attempt to win over political centrists in a state that's been trending blue of late, but where a plurality of voters doesn't identify with either party. The pick appears tailor-made to push back against frequent Democratic attacks tying Stapleton to President Donald Trump, who remains popular among Colorado Republicans, but sports dismal approval ratings among the rest of the electorate.

"I needed to find the person that was the most competent, able, and intellectually adept," Stapleton said in explaining his choice. "[Someone] that I had a professional rapport with, that I had worked on consequential legislation with, that I knew could reach across the aisle, that I knew Democrats by-and-large held in high respect and high esteem."

Democrats, meanwhile, have taken the opposite approach, nominating a candidate in U.S. Rep. Jared Polis who is well to the left of the current Democratic governor, John Hickenlooper, a political moderate. Polis has endorsed an assault weapons ban, a universal health care program similar to Medicare, and converting the state to 100 percent clean energy by 2040.

Polis announced earlier in July that Dianne Primavera, the CEO of Susan G. Komen Colorado, would be his lieutenant governor if he's elected in the fall. Primavera, 68, is a four-time cancer survivor who served eight years in the state House, representing a suburban Denver district.

Now that tickets for each party are filled out, the campaigning can begin in earnest. That's something Stapleton picked up on in his remarks as he said he would debate his opponent "as often as possible."

"I cannot wait to debate Jared Polis," he said. "Sign me up. I'm ready to go."

CPR's Nathaniel Minor and Megan Verlee contributed to this report.