Democrat Mark Kelly defeats Republican Martha McSally in Arizona Senate race

Democrat Mark Kelly has defeated Republican Sen. Martha McSally in Arizona, NBC News projected on Friday, giving Democrats a Senate pickup in the state.

Kelly, a former NASA astronaut, declared himself the winner earlier in the week.

"I am deeply honored that Arizonans have trusted me to be their next United States Senator and to serve in this seat once held by Senator John McCain," he said in a series of tweets Wednesday night.

"We woke up today still facing a pandemic, a struggling economy, and deep division in our country," he wrote. "We need to slow the spread of the virus, get our economy back on track, and defend health care protections for people with pre-existing conditions. And I know that together, we can."

Kelly, 56, is the husband of former Rep. Gabby Giffords, who survived being shot in the head in 2011 at a constituent event. The couple founded the Giffords Foundation, which supports gun control laws around the country.

The win puts both of the state’s Senate seats in the hands of Democrats - Kelly and Kyrsten Sinema, who was elected in 2018. Sinema congratulated Kelly in a tweeted statement Wednesday. "I am confident Mark will uphold the Arizona values of seeking common ground and putting country above party," she wrote.

The win solidifies Arizona’s swing-state status after years of Republican control, and comes as Democrats suffered a series of setbacks in their hopes of taking control of the Senate. They flipped one seat in Colorado, but lost another in Alabama and their big-money pushes aimed at unseating Sen. Lindsey Graham in South Carolina and Sen. Susan Collins in Maine both failed.

Although they held a seat in a tight race in Michigan, they're also trying to flip a seat where they're currently trailing in North Carolina and two seats in historically conservative Georgia, at least one of which is projected to head to a runoff on Jan. 5.

Kelly, in his first bid for public office, ran as a moderate who would be above the partisan bickering in Washington.

McSally was appointed to the seat in 2018 after the death of John McCain. Tuesday was a special election for the last two years of McCain’s term — the winner on Tuesday will have to run for re-election in two years — and was viewed as a must-win for Democrats' Senate hopes.

McSally trailed Kelly in the polls throughout the race and raised significantly less money.

McSally, a former Air Force pilot who opposed Donald Trump in 2016, found herself in a difficult position trying to hold on to the president’s base supporters while also appealing to moderates who would decide the election. McSally campaigned on multiple occasions with Trump and did little to distance herself from his administration.

Trump also created unique problems for McSally in Arizona because of his unpopularity with older voters, suburban voters and Mormons, key voting groups in the state. The Republican Party’s relative stability among some Hispanic voters also did not benefit McSally quite as much in Arizona, where most of the fast-growing Hispanic population is Mexican American, a group that tends to be less conservative than Cuban Americans.

McSally argued that despite Kelly’s independent rhetoric, he would vote to advance a liberal agenda if he were elected, echoing an attack Trump frequently used against Joe Biden and calling him “counterfeit Kelly.”

Kelly repeatedly dodged questions about whether he would vote for Sen. Chuck Schumer, the Democratic leader, to be majority leader if the party takes control of the Senate, and refused to stake out a position on whether he would vote to eliminate the filibuster.

In his tweets Wednesday, Kelly said, "I am preparing for the job of being an independent voice for all Arizonans, regardless of who they voted for."