Senate Republicans’ primary woes are back, with a Grand Canyon-sized vengeance.

President Trump is heading to Arizona for a Tuesday campaign rally where he’s expected to take aim at primary-plagued Sen. Jeff Flake (R-AZ).

The event marks the unofficial kickoff of a primary election cycle that risks going sideways on a party that had finally felt like it had figured out how to contain its congressional primary problems.

For two elections in a row, the Senate GOP establishment managed to steamroll the type of fatally flawed gaffe-prone candidates that cost the party the majority in 2010 and 2012, spending heavily on their preferred candidates to whack-a-mole underfunded and flawed challengers in places like Mississippi, North Carolina and Kansas.

But in the 2018 cycle party strategists face a chaotic map exacerbated by a petulant president who seems more interested in settling scores with his own party’s critics than defeating vulnerable Democrats.

“I can’t think of a quicker way to harm Senate Republicans than to target a sitting incumbent instead of targeting the 10 Democrats who are up for reelection in states he’s won. It’s really a remarkable and harmful situation,” said GOP strategist Brian Walsh.

Republican incumbents face Trump-fueled insurgencies in Arizona and Nevada, where Republican Sen. Dean Heller is caught between a GOP base that’s been unhappy he hasn’t been more willing to embrace Trump and a general electorate in a Hispanic-heavy state that Hillary Clinton carried. He infuriated both by waffling over Obamacare repeal.

And the downside of having 10 Democratic incumbents up for reelection in states Trump carried are a bevy of potentially messy primaries for the right to face them.

GOP primaries have already gotten ugly in Indiana and West Virginia, with candidates lobbing bombs at each other that could wound whoever wins the primary, while GOP strategists have wary eyes on developing primary races in Wisconsin, Florida and Ohio.

In deep red Alabama, some Republicans quietly worry that hardline religious conservative Roy Moore (R), the first-place finisher in the GOP’s primary, could give Democrats a tiny glimmer of hope for a win if he defeats appointed Sen. Luther Strange (R-AL) in next month’s primary runoff.

Even if their best candidates all win, primaries are already forcing GOP candidates to bear-hug Trump when it would serve them better for the general election to get some distance from the president — while blowing through badly needed campaign funds.

“It’s kind of a new purity test. It’s no longer about who’s the guy who says no to every spending bill, it’s who’s the guy who stands by Trump and who’s the guy who was too much of a pussy to stand by our hero president,” said one GOP strategist involved in a contested Senate primary. “It’s problematic.”

Some Republicans are also frustrated that Trump is using his bully pulpit to push around his own party rather than take on red-state Democrats and boost their preferred candidates where he remains popular. While he endorsed Strange, his support has been rather tepid, to say the least:

Congratulation to Roy Moore and Luther Strange for being the final two and heading into a September runoff in Alabama. Exciting race! — Donald J. Trump (@realDonaldTrump) August 16, 2017

Nowhere is the Trump-fueled party fission more troublesome than Arizona.

Flake is facing a primary challenge from former state Sen. Kelli Ward (R), a candidate most mainline Republicans believe would hand Democrats a winnable race.

“That’s the deep concern with someone like Kelli Ward. She’s in the same camp as Christine O’Donnell, Todd Akin and Richard Mourdock,” said Walsh, who was a top staffer at the National Republican Senatorial Committee in 2010 and 2012 when gaffe-prone candidates won primaries in Delaware, Missouri and Indiana as well as Nevada before costing the party those seats.

Flake has gone out of his way to directly antagonize the president, penning an op-ed and a book blasting the president and warning that the GOP “lost our way and began to rationalize away our principles” in supporting him.

Trump responded by calling Flake “toxic” — and touting Ward’s candidacy.

Great to see that Dr. Kelli Ward is running against Flake Jeff Flake, who is WEAK on borders, crime and a non-factor in Senate. He's toxic! — Donald J. Trump (@realDonaldTrump) August 17, 2017

Billionaire Robert Mercer, one of Trump’s top donors, recently cut a $300,000 check for Ward (he gave her twice that much last cycle).

Republicans believe that Flake starts the race with the upper hand in the primary. Ward is viewed as a fringe figure by many Republicans, and Sen. John McCain (R-AZ) already defeated her by a 13-point margin in a 2016 primary by branding her “Chemtrail Kelli.”



But Flake isn’t as well-known as McCain, and he’s done a lot more to rile up Trump’s backers. His views on immigration and trade are at odds with many in the party base. And Ward isn’t Flake’s only threat: Arizona state Treasurer Jeff DeWit (R) and former state GOP chairman Robert Graham, both Trump allies, are eying campaigns as well, with the quiet encouragement of some White House staff.

It’s unclear whether a DeWit or Graham candidacy would help Flake by splitting the anti-Flake vote with Ward or hurt him because both are viewed as much more formidable candidates.

While the Flake-Trump feud threatens to rage for months through next August’s late primary, Democrats are excited that Rep. Kyrsten Sinema (D-AZ), a highly touted candidate, is expected to run and have another solid possible option with Phoenix Mayor Greg Stanton (D).

There have been rumors Trump would use the Phoenix stop Tuesday to endorse one of Flake’s primary foes, though sources close to the White House say it’s a lot more likely that he is heading there to announce a presidential pardon of controversial former Maricopa County Sheriff Joe Arpaio. Still, he’s widely expected to take shots at both Flake and Sen. John McCain (R-AZ), who helped sink the GOP’s Obamacare repeal efforts.

Members of Senate GOP leadership are not-so-subtly making a show of support for Flake ahead of Trump’s trip:

Arizonans are well-served by the principled leadership of @JeffFlake. He always fights for what's best for #AZ & we need him in the #Senate. — JohnCornyn (@JohnCornyn) August 21, 2017

.@JeffFlake has won more conservative battles than most. Never grandstands. Just gets it done for AZ, USA. — Sen. John Barrasso (@SenJohnBarrasso) August 21, 2017

Flake’s campaign voiced a hope, likely optimistic, that the president won’t pick a fight during his visit.

“Senator Flake is focused on fighting for our state, and he hopes the president will speak constructively about moving forward with tax reform, border security, and other important issues facing our country,” said Flake campaign spokesman William Allison.

But Flake’s close allies admit he’s no shoo-in for reelection. And they joined other Republicans in wishing Trump would spend more time targeting Democrats and less time going after his own party.

“There’s no question Flake was going to have a very tough fight anyhow and having Trump on the other side is going to make it very difficult,” former Rep. Jim Kolbe (R-AZ), a Flake backer and Trump critic, told TPM. “It’s not helpful for the party to have this kind of internecine warfare going on.”

This post initially misstated the year in which McCain defeated Ward in a primary.