Mark Kelly, the retired astronaut and husband of former Rep. Gabrielle Giffords, launched his campaign to run for the U.S. Senate seat once occupied by the late John McCain.

Kelly is the first Democrat to enter the field ahead of 2020 and is widely seen as a formidable candidate given his biography and likely ability to raise the millions of dollars needed to take on the GOP's incumbent candidate, Sen. Martha McSally.

McSally was appointed to the seat by Gov. Doug Ducey late last year and it is unclear if she will face a competitive primary challenger as she did in 2018. McSally lost her run for the Senate last year to Democrat Kyrsten Sinema and, although she is seen as vulnerable by more liberal groups, this time she will be running as a sitting senator.

During a phone interview from his home in Tucson, Kelly offered a glimpse of the type of campaign he hopes to run. Like Sinema did in 2018, Kelly is casting himself as an almost apolitical figure who can work in a cooperative spirit, even in today's hyper-partisan environment.

Kelly, 54, intends to focus on the pocketbook issues that resonate with everyday Arizonans, from health care to jobs and climate change.

"I come at this not as a partisan," Kelly told The Arizona Republic, "but as a patriot and somebody who really cares deeply about our country and the direction it's been over the last several years. And I think of myself and I think Arizonans like the people they elect to be someone independent.

"And I feel that way, that I'm not going to look at these issues through a partisan lens, but as somebody that cares about the people here in Arizona and people in the country, and look at these things based on data and science and facts and with a sense of independence."

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Kelly said he will also be talking about gun control, the issue that he and his wife have spent years advocating for, particularly after the 2012 mass shooting at Sandy Hook Elementary School in Newtown, Connecticut.

"I care deeply about that issue and it will be a part of this campaign," Kelly said, adding that policymakers can protect the rights of gun owners while keeping communities and families safe from gun violence.

Asked how he would work with President Donald Trump's administration, Kelly said: "I'm going to be focused on Arizona and not what is going on in the White House."

Kelly announced his run during a four-minute video featuring cinematic views of the desert and intimate video of him with his wife, who survived an assassination attempt at a 2011 constituent event near Tucson. Six people died and 12 others were injured.

In the video, Kelly recounts his flights to space, his childhood, and his service in the U.S. Navy as combat pilot and engineer. He recalls seeing his wife for the first time after the shooting, and helping advocate for her in the years that followed. He learned from her how policy can be used to improve people's lives.

"Arizonans are facing incredibly challenging issues here in the years to come: access to affordable health care, the stagnation of wages, job growth, the economy, as the climate warms we're going to have more drought here in the desert," Kelly says.

"Solving some of the hardest problems requires one thing, and that's teamwork. … Partisanship and polarization and gerrymandering and corporate money have ruined our politics and it's divided us. I care about people. I care about the state of Arizona. I care about this nation. So because of that, I've decided that I'm launching a campaign for the United States Senate.

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"We've seen this retreat from science and data and facts, and if we don't take these issues seriously, we can't solve these problems."

The video ends with Kelly and Giffords sitting on a couch, "Damn the torpedoes," he says.

"Full speed ahead," they say together.

Fundraising first priority for Kelly

Kelly likely will focus much of his energy during the next several months on generating substantial money for his campaign and meeting with voters.

Kelly doesn't know Sinema well, but said they met recently.

"I really respect her a lot," he said. "I had a meeting with her the other day and she gave me some great advice. ... She told me to work hard."

Kelly could replicate Sinema's path to victory in 2020 by winning over the same type of moderate Republican voters and independent voters who were not swayed by McSally's message.

RELATED: Group says McSally most vulnerable senator up for election in 2020

In 2018, McSally leaned in on her relationship with Trump, even after winning the primary election. The strategy was a misfire.

“I think Republicans are worried about almost every match-up,” said Jennifer Duffy, who analyzes U.S. Senate races for the influential, nonpartisan Cook Political Report in Washington, D.C. “They lost a Senate seat in a non-presidential year in Arizona. And to put it in perspective: If Democrats really want to make a play for the majority, they have to win Arizona.”

Asked how he would fare in a match-up against McSally — the nation's first female combat fighter pilot — the retired astronaut said his focus will be on telling his story to voters.

"I don't look at this as taking on anybody," he said. "I'm going to travel around the state, I'm going to listen to what they care about … Why I'm the best person to represent them in the United States Senate. I come at this from a different set of experiences, even than Senator McSally. I had to do really complicated things and orbit this planet with international partners. It was critical that we figure out a way to collaborate with people that, in the case of the Russians, were our adversaries.

"It's a hard thing to do. I don't see that from this United States Senate."

Kelly's announcement comes a few days after former Arizona Attorney General Grant Woods, a Republican turned Democrat, announced he would not be getting in the race. Democratic Rep. Ruben Gallego is also considering a run for the seat. He said in a Twitter post Tuesday that he is seriously weighing a bid for the seat.

"I'll be making a final decision and announcement soon," Gallego, of Phoenix, tweeted.

The winner of the 2020 special election would have to run again in 2022 for the full six-year term.

McSally did not weigh in Tuesday about Kelly's announcement. But the Republican National Committee and the National Republican Senatorial Committee pressed Kelly to say where he stands on more liberal positions, such as the Green New Deal.

Introduced last week by Sen. Edward Markey, D-Mass. and Rep. Alexandria Ocasio-Cortez, D-N.Y., the deal outlines principles of a plan to both fight inequality and climate change. Kelly said Tuesday he had not read the entire proposal.

"I really care about the planet," he said, noting he saw from space how dramatically the planet changed from the time he first flew to space in 2001 and then returned a decade later.

"When a guy in space can look down over a decade and can see a planet that is now going through this phase of massive deforestation, with that carbon that was sequestered now being released into the atmosphere and the consequences of that, it's pretty frightening," he said.

Renae Eze, an Arizona spokeswoman for the RNC, said Kelly's "flashy digital ad left a lot to be desired — like where he stands on issues important to Arizonans, which won't do him any favors in the tough Democratic primary he's facing. Martha McSally has been clear where she stands since before day one."

So far, no other Democrats have announced their candidacies for the Senate.

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Kelly grew up in New Jersey as the son of two police officers.

He received a degree in marine engineering and nautical science from the U.S. Merchant Marine Academy, graduating with highest honors in 1986, according to his biography with NASA. He also has a master’s degree in aeronautical engineering.

During his military career, Kelly picked up awards ranging from the Distinguished Flying Cross to the NASA Exceptional Service Medal. He flew 39 combat missions in Operation Desert Storm and logged more than 5,000 hours in 50 different aircraft, NASA reported.

Kelly announced his retirement from NASA in June 2011, five months after Giffords was shot. He co-founded Americans For Responsible Solutions, a gun-control organization, which has since been renamed as Giffords.

Republic reporter Ronald J. Hansen contributed to this report.