Mark Kelly vs Martha McSally: Why Democrats See Hope on Supreme Court Fight

“We’d given this no thought prior to yesterday’s news,” said Daniel Scarpinato, chief of staff to Gov. Doug Ducey, a Republican who supports Mr. Trump. “This all seemed theoretical. Now it is not. At first blush, it appears we have a limited role. But we are going to research the law and we are going to follow it.”

Mr. Kelly, a former astronaut who is married to former Congresswoman Gabrielle Giffords, holds a steady and substantial lead in a state that seems to be tilting away from Mr. Trump after his 4-point margin of victory in 2016. Mr. Kelly held an 8-point lead over Ms. McSally in a recent New York Times/Siena College poll.

Mr. Kelly has emphasized local issues to avoid being perceived as too closely associated with the national Democratic establishment, given that independence is a prime political selling point in this western state.

In a statement Saturday evening, Mr. Kelly said that the nomination should wait until after the election. “This is a decision that will impact Arizonans, especially with an upcoming case about health care and protections for pre-existing conditions,” he said. “Arizonans will begin casting their ballots in a few weeks and I believe the people elected to the presidency and Senate in November should fill this vacancy.”

On Friday, Ms. McSally — who has adopted a Trumpian approach that includes attacking the news media — announced that she backed a plan by Senator Mitch McConnell to force a floor vote on a nominee while Mr. Trump was president, saying she would vote for whomever he named.

At 8:49 p.m. she tweeted out her condolences to Justice Ginsburg’s family; 15 minutes later, she wrote, “This U.S. Senate should vote on President Trump’s next nominee for the U.S. Supreme Court.”

Within 24 hours of Ms. McSally’s tweets, the 3.14 Action Fund, a pro-Democrat political action committee, seized on Ms. McSally’s statement in a fund-raising email. “Within minutes of learning of a Supreme Court vacancy, Martha McSally became the FIRST Senator to announce she will vote for ‘WHOEVER’ Trump and McConnell tell her to as soon as possible,” the solicitation read.