Rep. Martha McSally won the Republican nomination for Senate in Arizona on Tuesday night, and will take on Democratic Rep. Kyrsten Sinema in the open-seat race as the Grand Canyon State appears poised to elect its first female senator.

McSally emerged from a divisive primary by tying herself to President Donald Trump, whom she had declined to support in 2016 following comments he made about groping women. She fended off attacks from former state Sen. Kelli Ward and controversial former Maricopa County Sheriff Joe Arpaio that she would not be a strong Trump ally.

With 3 percent of precincts reporting, McSally led with 51 percent of the vote when The Associated Press called the race. Ward trailed with 29 percent and Arpaio with 20 percent. The results were largely from mail-in ballots.

On the Democratic side, Sinema was comfortably ahead of lawyer Deedra Abboud, 82 percent to 18 percent, when the AP called the race after returns from 213,000 mail-in ballots.

The seat opened when GOP Sen. Jeff Flake, a vocal Trump critic, announced his retirement.

The primary was just a few days after the state’s senior GOP Sen. John McCain died of brain cancer. Sinema and McSally both referenced the late senator in their statements Tuesday night.

Sinema’s campaign announced she and her team would not be campaigning Wednesday or Thursday to pay respects to McCain, who will be memorialized in Arizona before services in the nation’s capital. 

“It’s up to all of us to follow his lead of always putting country over party,” Sinema said.

McSally planned to lead her primary victory party in a moment of silence for McCain, according to excerpts of her remarks. She recalled meeting him when she first ran for Congress in 2012.

“Sen. McCain was an American hero,” McSally said. “He paid an unfathomable price for our freedom … and upon returning home continued to serve with conviction, honor, and sacrifice for his entire life.“

McSally had crafted a reputation as a more moderate member of Congress over her two terms representing the swing 2nd District based in Tucson. But in the Senate primary, she touted her conservative credentials and embraced Trump, who won the state by 4 points in 2016.

Some Republicans viewed McSally as their best chance for keeping the seat, given her experience in Congress and her military background as the first female pilot to fly in combat.

McSally might first have to work to unite Republicans behind her, given that she received a slim majority of votes when the AP called the race. Ward has declined to say that she would back McSally, but Arpaio said in a recent interview with Roll Call that he would back either candidate in the general election since Trump would also likely back the GOP nominee,

Both sides are gearing up for a competitive general election, with a sprint to early October when mail-in ballots are sent out to voters. Republicans acknowledge that Sinema is a formidable opponent with her fundraising ability and work ethic. The former state lawmaker, once known for her more liberal positions, has tacked to the center since her election to Congress in 2012.

Sinema had largely gone unchallenged on the airwaves until recently, when McSally launched an attack ad criticizing her for protesting military action while McSally was serving abroad.

Both lawmakers are known as strong fundraisers, but Sinema starts the race with a financial advantage. Most of her spending thus far has been on ads aimed at independent voters.

Sinema had $2.5 million in her campaign coffers at the end of the pre-primary reporting period on Aug. 8, according to Federal Election Commission records. McSally had $1.9 million in cash on hand.

Outside groups are also gearing up for a fight. Defend Arizona, a super PAC backing McSally, has already reserved $4.9 million in television time for general election ads. In Sinema’s corner, the new super PAC Red and Gold is also expected to spend this fall.

Inside Elections with Nathan L. Gonzales rates the Arizona Senate race a Toss-up.

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