Democratic Rep. Ruben Gallego, who contemplated a run for the U.S. Senate in 2020, is putting his full political weight behind Mark Kelly, who is seeking the party’s nomination in the special election.

Gallego, a three-term congressman, is campaigning alongside Kelly on Thursday afternoon at a downtown Phoenix eatery, and future appearances are in the works, locally and nationally.

Gallego’s support could bring Kelly added credibility with the more liberal wing of the state’s Democratic electorate — a group that may view Kelly’s centrist candidacy suspiciously and wants a candidate who will vocally oppose President Donald Trump and his policies.

Gallego, 39, also could help deliver other key constituencies, such as Latinos, young people and Maricopa County voters who may not be as familiar with Kelly's biography. Gallego represents Arizona’s reliably blue 7th Congressional District, which encompasses parts of Phoenix, Glendale and Tolleson.

Kelly, a retired astronaut and former Navy combat pilot, lives in Tucson and is a political newcomer who is untested as a candidate.

Gallego said he will be vouching for Kelly both in Arizona and out of state.

"I'm going to be out there advocating, stumping for him, making sure that we're getting out the Latino vote, getting out the youth vote, getting out the veteran vote — everything we can to make sure we have another successful run for the Senate," Gallego told The Arizona Republic Wednesday night. "We need to win this race, and the person who is most likely to win is Mark Kelly."

In a written statement to the newspaper, Kelly acknowledged the difficult political terrain ahead.

"I have great respect for my fellow veteran Ruben Gallego for his service to Arizona and our country," Kelly wrote. "This is going to be a tough campaign, and it’s going to take allies like Congressman Gallego who know their community and know the issues facing Arizonans. Plus, it's always good when a Marine has your back."

Kelly appears on track to run a non competitive primary. If he wins the Democratic nomination, he almost certainly will face Republican Sen. Martha McSally in the 2020 general election.

McSally, who served in the House of Representatives and is a retired Air Force combat pilot, has seemingly consolidated the support of the GOP establishment in Washington and avoided a primary opponent in Arizona.

Democrats are eying the Senate seat as a potential pick-up that could help swing control of the chamber to them. The Cook Political Report and the website Sabato's Crystal Ball have classified the race a "toss-up."

McSally lost her 2018 campaign for the Senate to Democrat Kyrsten Sinema. It was the first time in 30 years that an Arizona Democrat had won a U.S. Senate seat.

Gov. Doug Ducey later appointed McSally to serve the remainder of the late Sen. John McCain’s term. The winner of the 2020 election must run again in 2022 to serve a full six-year term.

Kelly has raised more than $4 million for his run, according to his first-quarter report filed with the Federal Election Commission. McSally has raised more than $2 million.

Gallego, a three-term congressman and a former Marine who served during the Iraq War, had been laying the foundation for a potential run until late March.

He bowed out after determining he would have to run a negative campaign, which could help McSally.

“It’s just not in the best interest of the state or the Democratic Party to be engaging in that,” he told The Republic at the time. “… If Republicans are excited to see a spirited and nasty primary, they’re going to have to look somewhere else, because I’m not going to take part in that.”

Have news to share about Arizona's U.S. senators or national politics? Reach the reporter on Twitter and Facebook. Contact her at yvonne.wingett@arizonarepublic.com and 602-444-4712.

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