PHOENIX — President Trump has had a Midas touch in recent Republican primaries, but he's set to play a hands-off role in the race for the GOP Senate nomination in Arizona, where the candidates are trying to get close to him.

Trump helped sideline Sen. Jeff Flake, R-Ariz., who Rep. Martha McSally, R-Ariz., former state Sen. Kelli Ward and former Maricopa County Sheriff Joe Arpaio are hoping to replace.

The lack of a presidential endorsement in the contest has led to a tug-of-war over the president, with each of the candidates arguing why they are the best to replace Flake and help advance the president's agenda. Trump is so far undefeated when weighing in on GOP primary fights this year.

"He's getting the job done. He's delivering on the promises he made to people in the election," said Rep. Debbie Lesko, R-Ariz., who hasn't endorsed in the race but expects McSally to win. "I think people are excited about that. He's a person that does what he says he's going to do."

McSally, who leads in the polls, has placed Trump front and center in her latest TV ad and does not hesitate to pump up her relationship with the president. In an interview following an event where she received the National Border Patrol Council's endorsement, the two-term congresswoman rattled off a list of events she's attended at the White House.

"I'm over in the White House all the time. ... I have a good relationship with him. I speak to him like a fighter pilot," McSally said, adding that her seat at the table is a political winner. "That even matters to Democrats. They like that their next senator is going to be at the table, is going to have access, is going to be in the room when these major discussions are happening."

On Monday, McSally received yet another boost when she was invited to the president's signing of the National Defense Authorization Act in Fort Drum, N.Y., and received a shout-out from Trump while onstage. While his comments fell short of an endorsement, McSally's campaign didn't hesitate to blast out the president's remarks.

"I've gotten to know her very well and she is terrific," Trump said.

McSally's perceived closeness to the president is laughed at by the other two candidates, however. The retired Air Force colonel has refused to reveal if she voted for the president and didn't endorse him prior to his 2016 election victory. This is led to accusations by Ward and Arpaio that she is a "Never Trump" Republican.

"She didn't know how to spell his name 'til last year," Arpaio said at a town hall last week. "The border wall? What wall? She didn't know what a wall was."

To Arpaio, Trump is the alpha and the omega. Trump pardoned Arpaio following a conviction for criminal contempt of court after he disobeyed a federal judge's order to stop racial profiling when detaining suspected illegal immigrants. He referred to Trump in an interview as "my hero."

Meanwhile, Ward is hoping the second time is the charm after losing to Sen. John McCain, R-Ariz., two years ago and banking everything on the president. Trump spoke highly of her last August when she was originally running against Flake. Since then, however, he's stayed silent.

Although many pan her for her bid against McCain, during which she mocked his age, she views it as a learning experience. While she defeated him in the voting on Election Day, the nearly monthlong period of early voting did her in, something she hopes to rectify.

"I've grown," Ward said. "I have a lot more confidence. ... I am ready. I thought I was ready the last time, but now I know that I am ready to be a United States senator."

Ward remains the only one of the primary candidates who has not pledged to support the Aug. 28 winner against Rep. Kyrsten Sinema, D-Ariz., in November. The former state senator believes there isn't much of a difference between her and McSally, but has said she will pledge to support the winner if they agree to a debate.

"It's hard to support someone when they hide," Ward said in an interview at her campaign headquarters. McSally says they already did before the Arizona Republic's editorial board, creating no need for any further debates.

For many in the state, the main question still centers around electability. In poll after poll, McSally remains the only one running competitively against Sinema in November, leading top Arizona Republican figures to line up behind McSally in recent weeks. Among those include former Sen. Jon Kyl, R-Ariz., and ex-Gov. Jan Brewer.

"The general election in Arizona for this Senate seat is potentially going to be difficult for a Republican because of the national mood and the Democrats have a very credible candidate running," Kyl said in a phone interview. "The question is ... which of the candidates running in the primary has the best chance to prevail."

"I think Martha McSally can," Kyl continued. "The other two I think just don't have the breadth that would appeal to enough Republicans and independents to prevail in that race."

Kyl noted that McSally comes from the Tucson-based Arizona 2nd District, at risk of going Democratic in November, and gives her an advantage in November.

GOP groups have also taken notice. America Rising, an anti-Democrat opposition research firm, has a tracker following Ward and Arpaio at campaign events throughout the state in the run-up to election day.

Along with trust for McSally comes a distrust for Ward from many Republican circles. Ward lost out a key endorsement from the Border Patrol Council, which backed Trump in March 2016, largely due past decisions, including told hold a town hall in 2014 that centered around "chemtrails."

"I don't think that she can win, period," said Brandon Judd, president of the National Border Patrol Council and an ally of Trump. "But when you look at the record and some of the controversial things she has said, you just don't know where she's going to come from at times. Sometimes she's spot on on issues and sometimes she's just way out in left field."

Judd specifically noted the "chemtrails" chatter from Ward as a reason.

Some Republicans even remain hopeful that Trump could weigh in on the race in the final week and tip the balance to McSally. Some Arizona-GOP political watchers believe the presence of Arpaio in the race has precluded Trump from offering any endorsement, but they readily note that anything can happen with this president.

"I think if he jumps in in support of Martha, I think that she easily wins the primary," Judd said. "I do think there's a possibility [of an endorsement]. He is stumping hard for Republicans and he's going to want a Republican that can actually win in the general. And Martha can win the general."

According to the latest RealClearPolitics average, McSally leads by eight points on Ward and 14 points on Arpaio. While McSally allies remain confident she'll hold on, they are holding their breath a little.

"I was confident of my own races and I'm confident of Martha's abilities here," Kyl said. But as Yogi Berra said, 'Predictions are hard to make, especially if they're about the future.'"