TUCSON, Ariz. — Kyrsten Sinema is trying to do something that no Arizona Democrat has done in 30 years: win a Senate election.

“We know we can win this election,” the three-term congresswoman told supporters packed into a union hall here Sunday. “This year, the votes in the Senate matter.”

And unlike Democrats in other red or purple states from Texas to Georgia who are running on decidedly progressive platforms, she’s making her case as a moderate with appeal to independents and pragmatic Republicans as she takes on GOP Rep. Martha McSally.

[McSally Bills Herself as ‘Firewall’ Against Democratic Takeover of Senate]

If Democrats have any hope of taking back the Senate or mitigating potential losses in red states, they need to win Arizona. But to do that, Sinema will also need to turn out the party faithful in high numbers.

It’s a delicate balancing act that few Democrats have been able to accomplish in Arizona in recent years — it’s been a decade since the party last won a statewide race.

“Midterms are hard [for Democrats] to win in Arizona, which tells you why Sinema is such a phenomenon, that she’s even keeping it close,” Democratic Rep. Ruben Gallego said in an interview at a Phoenix coffee shop.

Democrats believe the state is trending in their direction, but it’s not clear if Sinema’s strategy will be enough to win this year. Inside Elections with Nathan L. Gonzales rates the race a Toss-up. Recent polls have shown Sinema’s once small, but steady, lead nearly evaporate, with McSally even inching ahead in some surveys. And a loss could have Democrats rethinking how they win a state like Arizona.

What to Watch in the Final Stretch of the Arizona Senate Race

Tightrope walk

Sinema does have a math problem. Republicans and those not registered with a party still outnumber registered Democrats in the Grand Canyon State.

That partisan divide makes some Democrats nervous. Karen Lieneke, a 65-year-old English as a second language teacher in Tucson, said she was “cautiously optimistic” that Sinema could actually win.

“The climate of fear and the climate of really raw politics is a wild card to me,” Lieneke said at the union hall.

Sinema, a former state legislator, has been helped by an aggressive ad campaign touting herself as a moderate and an independent lawmaker. She was on television as early as April, and went largely unchallenged on the airwaves as McSally battled two others in a competitive GOP primary.

Democrats say Arizonans recognize that the once self-described “most liberal legislator in the state”  has shifted to the center since first coming to Congress in 2012. In a recent radio interview, Sinema said it was difficult to call herself a proud Democrat, opting instead to call herself a “proud Arizonan.” 

She has acknowledged her ideological shift — an analysis by CQ Vote Watch found she supported the president’s priorities 60 percent of the time, the third-highest score among House Democrats. 

“Over the years I am proud to say I have taken the time to learn and grow and occasionally change my opinion,” she said at a recent debate.

But Republicans are trying to paint Sinema as a radical liberal, and highlighting past footage of her knocking the Grand Canyon State.

“You guys haven’t reported on Sinema calling our state crazy and saying we’re the meth lab for democracy,” McSally chided reporters after touring a technical school in Avondale on Wednesday. “Every single day something is coming out related to her campaign that’s actually legit, her showing disdain for our state.”

The National Republican Senatorial Committee in a recent television ad used video of Sinema implying in 2011 that Arizona produces “crazy,” but the tactic might not work with everyone. 

Dorothy Byrne, a 77-year-old Phoenix resident not registered with any party, is backing Sinema this year (and all Democrats to protest what she sees as a divisive GOP-controlled government).

“Tell us what you want to do today,” Byrne said Monday while waiting to hear Democrat Hiral Tipirneni address a town hall meeting in Arizona’s 8th District. “I don’t care what you did 20 years ago. I didn’t do the same things 20 years ago.”

Byrne supported GOP Sen. John McCain in 2016, but wasn’t inclined to support McSally this year.

“We need things back a little more in balance,” she said.

Democrats see a path to victory with the support of nonpartisan voters like Byrne and moderate Republican women. But Sinema also has to make sure that moderate image doesn’t turn off loyal party members, whom she also needs to turn out in large numbers.

Turning blue?

Arizona may not yet be a blue state, but it isn’t as red as it used to be. President Donald Trump won it by 4 points in 2016, smaller than his margin in the traditional swing state of Ohio. 

Democrats supporting Sinema packed two union halls Sunday as she traveled from Tucson to Phoenix to stress the importance of voting early. Not everyone in the room was thrilled with her moderate positions, but they still showed up.

“I agree with the president essentially never,” Emily Dacey, 31, said at the Phoenix event, adding that she wished Sinema would be more adamantly opposed to Trump. 

“But I’m not getting to choose my ideal person,” Dacey said. “I’m getting to choose between Kyrsten Sinema and Martha McSally. And I’m here to fight for her because she still stands more with me than McSally does.”

Watch: McSally Defends Health Care Record in Testy Media Exchange

Democrats are touting an extensive field operation as evidence of energy on the left. The joint effort between the Arizona Democratic Party and Sinema’s campaign boasts 25 field offices and 4,000 volunteers across the state. Over the weekend, volunteers knocked on 65,000 doors, the most ever in one weekend, according to Sinema’s campaign.

Gallego said there was a focus on getting out the vote this year and that turning out Latino and Native American voters were key to a Democratic victory.

But so far, early ballot returns give Republicans an edge. As of Wednesday evening, 44 percent of the early ballot returns were from Republicans, while 33 percent were from Democrats.

Gallego, who is weighing a Senate run of his own in 2020, said future efforts may have to concentrate more on turning out the Democratic base. He said an emphasis on voter registration could close the gap as the state shifts demographically with its growing cities.

“Arizona’s changing. It just is,” said DJ Quinlan, the former executive director of the state Democratic Party. “The notion that Arizona is this bright red state is no longer accurate. It’s going to be a swing state from this point forward”