FILE -- In this Nov. 16, 2006, file photo Sen. John McCain, R-Ariz., pauses while speaking to the GOPAC Fall Charter Meeting in Washington. McCain's family said in a statement on Aug. 24, 2018, the Arizona senator has chosen to discontinue medical treatment for brain cancer. The 81-year-old McCain has been away from the Capitol since December. McCain's face bears a scar from skin cancer surgery in 2000. (AP Photo/J. Scott Applewhite, file)
Who will fill John McCain's Senate seat?
02:04 - Source: CNN
Phoenix CNN  — 

In replacing John McCain, Arizona Gov. Doug Ducey is set to make the most important decision of his political career – one that could determine his future in Republican politics.

Ducey faces massive, competing pressures in selecting someone to fill McCain’s Senate seat until a 2020 special election. Donald Trump and his supporters will want a reliable vote in the Senate and will blame Ducey if his appointee breaks with the President. McCain’s camp, meanwhile, could prefer someone in the “Maverick” mold or a placeholder who wouldn’t seek re-election.

Then there’s Arizona’s rapid evolution from reliably Republican to a diverse swing state where Senate seats won’t be easy for the GOP to hold.

Republicans say Ducey is aware of those competing factors but aren’t sure how he’ll balance them.

“Of course he’s considered what he would do,” one Republican strategist close to Ducey said. “Of course. It’s a very high responsibility.”

But, the strategist said, Ducey directed aides and advisers to “not engage in any kind of speculation at all” about the appointment – including discussing what qualifications and background Ducey might be looking for – until after McCain was buried in Annapolis, Maryland, on Sunday.

“I don’t think he wants to look backward. He’s a young man, politically speaking, and so he wants to be able to narrate something about him here too,” said veteran Arizona GOP strategist Chuck Coughlin. “Arguably this is the biggest decision of his career.”

The former chief executive officer of Cold Stone Creamery, Ducey brought a cold, corporate style with him into the political world. “If you cross him, you’re done,” one Arizona Republican said. “He’s got a very tight hand on that ship.”

For a governor, Ducey’s political orbit is small. His chief of staff, Kirk Adams, is a former Arizona House speaker who serves as Ducey’s primary go-between with state lawmakers. Danny Seiden, who left Ducey’s office to join a law firm, is another government and campaign veteran close to Ducey. Washington-based consultant Doug Goodyear, who maintains a Scottsdale home and was Ducey’s neighbor, is close to the governor. And Republican strategist Danny Diaz was Ducey’s general consultant before he managed Jeb Bush’s presidential campaign.

Ducey has a working relationship with Trump, those close to him say – and Trump’s endorsement of Ducey after Tuesday’s primary could be read as a sign that the White House is paying attention to his moves – but he’s closer to Vice President Mike Pence, who was elected governor of Indiana two years before Ducey became governor of Arizona.

People in Ducey’s inner circle told friends as recently as Wednesday that they weren’t sure who the governor would choose.

The only word from Ducey’s office has been the lone statement senior adviser Daniel Ruiz has sent reporters since the weekend.

“Out of respect for the life and legacy of Senator John McCain and his family, Governor Ducey will not be making any announcements about an appointment until after the Senator is laid to rest. Now is a time for remembering and honoring a consequential life well lived,” Ruiz said in the statement.

While Ducey’s camp is quiet, speculation among Arizona Republicans has ranged from several women Ducey has appointed to state government posts to Cindy McCain.

Former Sen. Jon Kyl, who retired more than five years ago and is seen as a potential placeholder until the special election in 2020, wouldn’t comment on whether he is interested in the job.

“I am not commenting on any of this until Senator McCain is laid to rest,” he said in an email.

Ducey is likely to look for someone who would have the support of McCain’s family, several Arizona Republicans said.

“I don’t think they get to decide, but I think that’ll certainly factor in,” said Constantin Querard, an Arizona Republican strategist.

Arizona held its primary for the seat of retiring Republican Sen. Jeff Flake on Tuesday. Rep. Martha McSally won a hard-fought three-way race and will face Democratic Rep. Kyrsten Sinema in November.

The prospect of another Senate primary – with outsider candidates like Kelli Ward and Joe Arpaio looming as possible contenders – is something national Republicans are likely to want Ducey to avoid.

Querard said former Rep. Matt Salmon and current Rep. David Schweikert are among the potential appointees who would be unlikely to face a challenge from the right.

“A lot of the other names you hear,” he said, “the first thought is, ‘Oh my gosh, we’re going to have another primary in two years.’”

Adams, Ducey’s chief of staff, is one possible contender. The downsides to an Adams pick are that he’s much like the governor: A relatively young white male in a state that has never elected a female senator, and where diversity could help the GOP hold a seat that is sure to be a top Democratic target in 2020. It’s the same problem that would come with appointing a current or former member of Congress like Salmon, Schweikert or another often-mentioned possibility, former Rep. John Shadegg.

Karrin Taylor Robson, a wealthy developer and member of the Arizona Board of Regents, is a potential choice that would please the GOP donor community in Arizona. Her father was a state Senate president and her brother was a Maricopa County supervisor who brawled with then-Sheriff Joe Arpaio.

State treasurer Eileen Klein, a chief of staff to former Gov. Jan Brewer and former member of the state Board of Regents, was appointed by Ducey to her job just months ago and is often among the first people mentioned by Arizona Republicans for the job. She replaced former state treasurer Jeff DeWit, who took a Trump appointment at NASA and, despite being close to Trump, is not seen as a candidate due to his history of brawling with Ducey.

Another possible contender is Barbara Barrett, a business executive and former ambassador to Finland. The knock on Barrett: Bad blood with McCain dating back to Barrett’s 1994 effort to oust Gov. Fife Symington, a McCain ally, in a Republican primary.

Correction: This story has been updated to accurately state when Jon Kyl retired from the Senate.