McSally lost a blistering Senate race two years ago, but was appointed to the state's other Senate seat weeks later. Now she's back on the ballot for round 2 — defending her seat against a more imposing opponent in Kelly, with his sterling resume, massive fundraising and popular wife, Gabby Giffords.

As McSally dashed between a tightly-packed schedule of events on a recent morning here — hours later, she would appear on stage at a rally with the commander in chief, soaking in the praise of the president and his supporters — her 2020 strategy was clear: run side-by-side with Trump, and turn Mark Kelly the astronaut into Mark Kelly the socialist.

It’s a tough sell. Kelly has no history in elected politics, no past votes to attack and a biography that has made him a sought-after Democratic recruit for years. But the fight might decide which party controls the Senate.

“That’s what’s at stake here,” McSally said, leaning over from the front passenger seat of her staffer’s car to emphasize her point to a reporter in the back. “It’s not whether you like him. It’s not whether you think it’s cool he was an astronaut, or I was a fighter pilot. It’s about what direction you want the country to go.”

As for that countdown clock: McSally checked it daily during her 2018 race against Kyrsten Sinema — and she resumed the habit last year when her campaign ramped up. McSally, who made history as the military’s first female fighter pilot to fly in combat, said she approaches the campaign "like these could be the last two years of my life" and would "never pull back from the afterburner."

This race, in a state Democrats think could be on the cusp of turning blue, is an expensive clash of heavyweight political biographies: McSally is a retired Air Force colonel. Kelly is a Navy veteran who flew four missions to space, commanded the space shuttle — then quit to return to Arizona to care for Giffords, who was seriously wounded in a 2011 assassination attempt.

McSally raised more money than every other Republican senator last year, topping Majority Leader Mitch McConnell and well-known stalwarts like John Cornyn (R-Texas) and Lindsey Graham (R-S.C.). But Kelly raised more than any senator or candidate of either party — $20.2 million — and had the biggest war chest entering 2020 of anyone on the ballot this year across the country.

McSally is relying on a resurgence of Arizona’s red tilt, making a hard play for the GOP base by aligning with Trump, who won here by 3.5 percentage points in 2016. She argues the left was “pretty on fire” in 2018, while rural Trump voters didn’t turn out to the degree they will this year — though the GOP governor who would later appoint her to the Senate, Doug Ducey, won reelection while Sinema peeled away crossover votes.

This year, McSally has taken a two-pronged approach: She's talking more about her past to improve her image compared to 2018, while also running a knock-down, drag-out campaign against Kelly. Her launch video released this month featured emotional testimonials from Arizona voters as she talked about her personal background, including her father’s death when she was 12 and surviving sexual assault when she was in the military. That same week, she launched her first TV ads bashing Kelly for supporting impeachment and tying him to Sen. Bernie Sanders (I-Vt.).

“We’re trying to win back over suburban, college-educated women. I’m a suburban, college-educated woman. That’s my demographic,” McSally said. “I broke barriers to pave the way for opportunities for them and their daughters.”

As for the attacks?

“Structurally, there’s people who love the president here. There’s some people who like his policies, maybe don’t like his demeanor,” she said. “There’s people who maybe took a protest vote against him in 2018, on me. But they’re not for socialism.”

McSally is no stranger to tough races: She lost a House race in 2012 by 2,454 votes, then won a rematch in 2014 by only 167 votes. She blew out her opponent in 2016 before leaving for the Senate race after the Republican incumbent, Jeff Flake, decided not to seek a second term after criticizing Trump.

Sen. Kevin Cramer (R-N.D.), who served with McSally in the House and now in the Senate, called her “tenacious as all get out.”

“We’d all love to draw a weak opponent, or none, if we can. But in Martha’s case, she’s never had that luxury,” Cramer said.

McSally is specifically working to improve her coverage in Maricopa County, the vast expanse that includes Phoenix and the majority of the state’s voters, which she lost in 2018. She’s started stacking events to spend entire days in one part of the county to avoid wasting time traversing myriad highways.

In Gilbert, a town of more than 200,000 people outside Phoenix, McSally sat down to talk local issues with the mayor outside a bustling coffee shop in the mild winter warmth before taking a walking tour of the small downtown, hitting up a few local spots to hand out pins for the town’s centennial. She talked with constituents and took pictures — including with one woman who asked about Trump’s rally and told her, “please more of them,” in reference to the attack ads against Kelly.

She also toured a local Bishop’s Storehouse run by the Mormon church and gave an update on her work in Washington, including talking about the seven bills she sponsored that were signed into law — she’s tied with Chuck Grassley (R-Iowa) for most among senators, according to GovTrack. She then squeezed in a roundtable with female small business owners at the local chamber of commerce, all jammed into five hours before she jetted across town to speak at Trump’s rally.

There, she bashed Kelly, telling the crowd he was “flying on Bernie Sanders’ wing, and I’m flying on your wing, President Trump.”

Democrats are just as eager to emphasize how closely McSally aligned with Trump. In an interview, Kelly said it's important to have independence representing Arizona, and McSally lacks it.

“We’ve seen that in this state before from other U.S. senators. I’m concerned that we’re losing that,” Kelly said, pointing to McSally's votes to repeal Obamacare and support Trump’s emergency declaration at the border, even though funds have been diverted from Arizona military projects to build the wall.

Democrats' campaign plan against McSally is essentially the same as in 2018: run a centrist against her, criticize her on health care and pre-existing conditions and attack her for being too aligned with Trump in a state the party believes will be a major presidential battleground. Democratic Arizona Rep. Ruben Gallego, a liberal who considered running for Senate but now supports and has campaigned with Kelly, said Arizona, with its increasingly diverse electorate, is trending toward Democrats — and McSally hasn't kept up.

“Things have only gotten worse for her” since 2018, Gallego said. "And I don’t see her trying to change course.”

McSally stood by her voting record with Trump — 91 percent in the Senate, according to FiveThirtyEight — saying it showed her colleagues were putting good legislation on his desk. She also defended voting to support the border emergency, saying Trump had the legal authority to declare it and blaming Democrats for creating a “false choice” between funding the military and border security.

McSally, who drew support from Trump's campaign last month for a brief confrontation with a CNN reporter in a Capitol hallway, got an energetic reception from the crowd at the Trump rally that evening. In conversations with attendees, most spoke positively about the senator, though with less enthusiasm than they had for Trump.

“Being the first female fighter pilot and stuff like that, I think, is a really cool thing to have under your belt,” Chris Montgomery, who works compliance at a bank in Phoenix, said about McSally. “Going up against an astronaut is never easy. But, like I said, I think she’s done a good job so far sticking it to their face.”

Kelly’s impressive biography is never far from mind in the race: His campaign liberally uses space puns in its public statements, and released their first TV ad last week introducing his biography to voters. Kelly himself is quick to reference it. During a visit to a public school with career training programs in Phoenix last week, Kelly met several students in scrubs and pointed to one who had gauze on his arm from having blood drawn. “I used to have to do that at NASA,” he said, adding that he needed the skill “in case you have to do it in space.”

A poll conducted by a Phoenix-based GOP firm this month showed McSally down 7 percentage points to Kelly and well defined among voters, with a 43 percent approval rating and a 46 percent disapproval rating. Kelly had 42 percent approval and only 24 percent disapproval, but one-third of voters didn’t know him.

That’s why Republicans leaped at the opportunity to tie him to Sanders’ surge. Kelly has said he’d support the Democratic nominee in November but emphasized his disagreements with the presidential frontrunner.

“There are policies that Sen. Sanders has and put out there that I don’t agree with, like taking away private health insurance from individuals. I’ve been very clear about that,” Kelly said in the interview. “I’ve also been very clear about the administration in the White House and the trajectory our country has been on. Elections are about choices.”

He declined to say who he would choose in Arizona’s presidential preference ballot on March 17 and demurred when asked if he could win the state if Sanders is atop the ticket.

McSally ran a burn-it-all-down general election against Sinema, throwing out attacks at a roaring pace in the ten weeks between her primary and Election Day. But she makes no bones now about already turning negative against Kelly, even as some Republicans privately worry she’s repeating mistakes from the last race. Facing a cash deficit that's likely to grow, McSally said she had to fight early to define the race when she saw the opening.

"It was right after the impeachment vote," said McSally. "It’s right as Bernie is surging, and people need to know that."