Ms. McSally had tried, and failed, to use the Supreme Court as an issue in the past: She ran Facebook ads showing her support for Brett Kavanaugh’s nomination during her failed 2018 race against Kyrsten Sinema, a Democrat, for the state’s open Senate seat. Ms. Sinema opposed Mr. Kavanaugh, but took pains to distance herself from party leadership, as Mr. Kelly has. (Ms. McSally was appointed in December 2018 to fill the seat vacated by interim Senator Jon Kyl.)
And appealing to her base comes with its own risks. In that regard, Ms. McSally is facing a dilemma confronted by many Republicans this year: How to retain the support of conservatives who back Mr. Trump without completely alienating suburban moderates?
Her strength is in rural Arizona, the most deeply red part of the state; she has consistently trailed in Maricopa County, home to Phoenix, which makes up 60 percent of the electorate.
Her team has put more energy into the county, a traditional Republican stronghold which is trending blue, but it has yet to yield results: Ms. McSally is on pace to lose the county by a far greater margin than her more than four-point deficit in 2018, according to recent polls. Embracing Mr. Trump’s Supreme Court plans could push that deficit even deeper.
Whatever happens, Justice Ginsburg’s death has reminded voters — if they needed any reminding — of the existential political issues at stake in this year’s election, and has focused renewed attention on a Senate race many had deemed a done deal.
At a Students for Trump rally earlier this month in Chandler, south of Phoenix, it took only a few minutes for the crowd to break out in chants of “fill the seat” as raucous supporters awaited the arrival of Donald Trump Jr.
“This state, whether you like it or not, could determine the future of America,” the younger Mr. Trump told a crowd of 800 who were packed, mostly maskless, into an event space that was supposed to hold 500. “If you would’ve told me that 10 years ago, I would’ve thought you were joking.”