McSally, the GOP establishment favorite, won 51.3 percent of the primary vote with 9 percent of precincts reporting, according to a projection from The Associated Press.

She beat two Republicans who ran to her right: former state Sen. Kelli Ward, who won 28.5 percent of the vote, and former Maricopa County Sheriff Joe Arpaio, who ended up with 20.2 percent.

Like other Republican primaries this year, the costly contest largely became a competition about which candidate was most closely aligned to President Trump, who opted not to endorse anybody in the race because of personal connections he had with all three of them.