PHOENIX — Democratic Rep. Ruben Gallego referred to himself as “a true progressive voice in Congress” in a fundraising email in 2022.

In 2018, he rallied alongside Sen. Bernie Sanders in his home state, saying facetiously: “President Trump is going to build a wall. It’s called the progressive wall — it’s all my brothers and sisters holding hands to stop Donald Trump.”

And when Sanders took the stage, he called Gallego and Rep. Raúl Grijalva “two leaders of the progressive movement.”

It’s not a label Gallego, who rose through the political ranks as a liberal firebrand, is embracing the same way now as he runs for Senate.

“I consider myself an Arizona member of Congress who works across the aisle with everybody,” Gallego told NBC News last week when asked if he still identifies as a “progressive.” Last month, Gallego allowed his membership in the Congressional Progressive Caucus to lapse after joining during his first term in Congress, a decision he claims was about finances. 

“The Progressive Caucus actually increased their dues tremendously, and that comes out of my staff pay, and so, you know, we have to make decisions,” Gallego said. Pressed again, he continued: “I work for Arizonans. And sometimes that makes me cross a lot of political spectrums.” 

Gallego’s shift of emphasis reflects several realities. He’s trying to jump from a congressional district President Joe Biden won 3 to 1 to a statewide campaign in one of the most tightly divided battlegrounds in the nation. And Arizona’s middle is up for grabs in the Senate campaign, which also features pro-Trump Republican Kari Lake in the race to replace Democratic-turned-independent Sen. Kyrsten Sinema.

Gallego’s congressional voting record has been an early line of attack for Lake.

“He’s more liberal than AOC. He votes with Biden 100% of the time,” Lake swiped during a rally in Cave Creek in mid-March. A FiveThirtyEight analysis of Gallego’s voting record shows the congressman voted with President Joe Biden 100% of the time during the 117th Congress. 

Gallego cast his record as in line with the state.

“I’m proud of my votes because they’ve been in lockstep with what Arizona needs,” Gallego told NBC News in Camp Verde. “Look at the individual votes, and you’ll see that there were votes that were beneficial to the state of Arizona,” he added, citing his votes for legislation bolstering tech jobs and expanding health care benefits for veterans. 

Lake has made her own notable political transformation. In 2008, she donated to Barack Obama’s presidential campaign in 2008. Now, she refers to herself as “Trump in heels.” But Gallego rarely brings up his probable opponent in November unprovoked. 

Last week, Gallego’s campaign announced that it raised $7.5 million in the first quarter of 2024, and major Democratic groups have already reserved more than $23 million in TV airtime to support his general election campaign. Meanwhile, Lake’s campaign claims it raised over $1 million at a Mar-A-Lago fundraiser featuring former President Donald Trump on Thursday. The campaign could prove to be the most hard-fought Senate race in the country. 

The path to politics

Gallego, 44, was raised in the suburbs of Chicago by a single mother after his father split while the future congressman was in sixth grade. Gallego, whose parents are Mexican and Colombian, went on to earn a scholarship to Harvard, where he studied international relations while working multiple jobs before joining the Marines and deploying to Iraq. 

Throughout his political career, which started in Arizona’s state House in 2010, Gallego’s lived experience has been reflected in the legislation he’s championed. In the state Legislature, Gallego fought to expand Medicaid for veterans and provide in-state tuition for former soldiers living in the state. And upon election to Congress in 2015, Gallego immediately joined the Congressional Progressive Caucus and vowed to fight for America’s working class. 

One past sign of Gallego’s alignment on the left: The congressman had mulled a Senate run in 2019, when he considered challenging now-Sen. Mark Kelly in a Democratic primary for Arizona’s other Senate seat. Grijalva and liberal groups were pushing him to challenge Kelly, a former astronaut who at that point did not have a political record, but Gallego ultimately declined to run.

Gallego instead enjoyed a different rise to national attention several years later, when he was a leading outspoken critic against Sinema, after she declined to support the party’s drive to abolish the filibuster in order to advance voting rights legislation and codify abortion rights into federal law. 

“She hasn’t had a town hall in three years,” Gallego told NBC News at a 2022 voting rights march in Phoenix, days after Sinema announced on the Senate floor that she would stand by the filibuster. 

“She would hear how worried we are about this country and how we need the Voting Rights Act to protect this country,” Gallego said.