In this Aug. 31, 2016, file photo, Republican presidential candidate Donald Trump arrives speak at a rally in Phoenix. | Evan Vucci/AP GOP on eggshells as Trump storms into Phoenix A sustained attack on vulnerable Sen. Jeff Flake could rupture the president's relationship with his party.

PHOENIX — President Donald Trump faces a decision on Tuesday evening with profound implications for his already strained relationship with the GOP: whether to attack a vulnerable Republican senator on his home turf.

White House officials won’t say exactly what’s on Trump’s agenda when he holds a campaign-style rally here. But it's widely expected he will go after GOP Sen. Jeff Flake, a loud critic of the president who recently published an anti-Trump manifesto, “Conscience of a Conservative.”


Whatever he says about Flake, the president is clearly determined to send a message. State Treasurer Jeff DeWit, who is weighing a primary challenge against Flake, will join the president on Air Force One on Tuesday, according to two people briefed on the plans. And the daughter of another potential GOP candidate, former state GOP Chairman Robert Graham, is slated to lead the Pledge of Allegiance.

In the days leading up to Trump’s Arizona trip, Senate GOP leaders have implicitly warned Trump that attacking Flake, who faces a treacherous path to reelection, would only serve to further rupture his relationship with a congressional GOP wing that he’s grown increasingly isolated from in recent weeks. It came after Trump, in a tweet after the Phoenix event was announced, called Flake “toxic.” The president had earlier threatened to spend as much as $10 million to take out the incumbent Republican.

Senate Majority Leader Mitch McConnell, Majority Whip John Cornyn, and National Republican Senatorial Committee Chairman Cory Gardner all declared that Flake had their full support.

On Tuesday morning, Senate Leadership Fund, a super PAC closely aligned with McConnell, will amp the pressure. The group is set to release a blistering digital ad campaign that targets Kelli Ward, a conservative former state senator and Flake primary opponent who Trump praised in a tweet last week.

The ad paints Ward as an extreme figure with “crazy ideas” who engages in “embarrassing behavior.”

People close to the group describe the offensive as part of a broader effort to show that any Trump-led push to undermine Flake, or any GOP incumbent, for that matter, won’t go uncontested.

"We're not willing to throw this Senate seat away to Democrats by nominating a fringe candidate like Kelli Ward," said Steven Law, Senate Leadership Fund’s president and a former McConnell chief of staff. The group is spending over $10,000 on the ad, which will be geo-targeted to people who attend the rally and will run for three days.

Law said he had not yet decided how much to spend to defend the senator but that he had begun talking to Republican Party donors about the race.

Trump’s fixation with Flake has been on display for months. Backstage before a campaign rally last fall, Trump raged to associates about the senator, who refused to endorse him. This year, the White House has met privately with three actual or prospective Flake primary opponents. One of Trump’s top campaign aides, David Bossie, has privately spoken to a former Republican congressman, Matt Salmon, about his interest in running.

And one of Trump’s top donors, the reclusive billionaire hedge fund manager Robert Mercer, has donated $300,000 to a pro-Ward super PAC — with more possibly on the way.

Trump’s decision to venture to Flake’s home state goes to what senior Republicans say is a much deeper concern: that the president seems more interested in exacting revenge against members of his own party than defeating Democrats. It is highly unusual for the president to openly campaign against a sitting member of his own party, let alone someone as vulnerable as Flake.

Yet he is not the only Republican in Trump’s cross hairs. Earlier this summer, as the health care debate consumed Washington, a White House-sanctioned super PAC launched an attack against another endangered Republican senator, Dean Heller of Nevada, over his reluctance to support the legislation. During a meeting at the White House to discuss the legislation with the Senate GOP Conference, the president appeared to joke about Heller’s political circumstances. “Look, he wants to remain a senator, doesn't he?” Trump asked.

“The president needs to decide not only on Tuesday but over the next 14 months whether he wants to help grow the Republican majority in Congress or whether he wants to engage in personal feuds that ultimately only help Chuck Schumer,” said Brian Walsh, a former top NRSC official. “It’s perplexed and frustrated many Republicans that the president hasn’t put his well-earned political capital to use in those states against the Democrats and instead has focused his energy and attention against the very senators whose support he needs today.”

Yet within the White House, there has been angst about how to handle the race — and particularly over Trump’s decision to promote Ward, who is widely regarded as a subpar candidate. Ward received just 39 percent of the vote when she unsuccessfully challenged GOP Sen. John McCain in 2016, and she recently came under fire for saying that McCain should step down “as quickly as possible” following his brain cancer diagnosis — remarks that were widely panned as insensitive.

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By highlighting Ward — as opposed to one of the other potential candidates considering a primary bid, such as stateDeWit or Graham — some White House aides are convinced that Trump may have actually made it harder to unseat Flake. There has been so much consternation over the issue that rally organizers have sought to deny Ward a speaking slot at the rally or even a seat in the VIP section, three people involved in the planning the event said. Ward, they worry, could use such prime real estate to advance the idea the president supports her.

GOP concerns about Trump’s Arizona rally go beyond Flake. Many in the party are worried that he will use the event to pardon controversial former Maricopa County Sherriff Joe Arpaio, an immigration hard-liner who in July was convicted of criminal contempt in a racial profiling case. Trump has said he’s considering a pardon, but it could reignite racial tensions that flared after the violence in Charlottesville, when Trump equated white supremacists with counterprotesters.

In the run-up to the event, Arizona officials said they were preparing for the worst and promised a substantial law enforcement presence.

Vice President Mike Pence is slated to join Trump at the rally, as is Housing and Urban Development Secretary Ben Carson, though some other senior Republicans are staying away. Neither Flake nor McCain is expected to attend. GOP Gov. Doug Ducey, who is thought to have national aspirations, will greet Trump at the Phoenix airport but won’t attend the event.

“Gov. Ducey’s focus has been working with law enforcement toward a safe event in downtown Phoenix for all those involved and in the area,” said the governor’s deputy chief of staff. “That will continue to be his priority during the event and afterwards.”

