Cox, an obscure businessman and perennial candidate, has been happy to trumpet the White House nod, though he spent months on the campaign trail portraying Trump as a virtual nonfactor for voters hungering for a new direction.

White House aides and outside advisers described a chief executive at greater ease with the daily realities of being the face of the party than ever before, including making endorsements and raising money — a characterization at odds with his iconoclastic approach in 2016 and with his idiosyncratic and mostly unsuccessful endorsement strategy in special elections since he took office.

These advisers say Trump has been flexible and accommodating to party goals during discussions — “willing to hear the arguments and put himself out there,” is how one person put it.

His willingness to go along with the candidates picked by party leaders points to the president’s growing comfort ahead of the midterm elections to set aside loyalty and support candidates with the best chance of winning. Trump also has settled personal rivalries in the name of unity, hewing to GOP mainstays and snuffing out the momentum of their would-be rivals trying to capitalize on his outsider persona.

Trump has cast aside some of his biggest rivalries with early endorsements. He’s already bestowed the imprimatur of the presidency on Republican Sen. Ted Cruz of Texas, a former presidential campaign opponent who derided him as a “pathological liar,” “utterly amoral,” “a serial philanderer” and “a narcissist at a level I don’t think this country’s ever seen.” And he endorsed former Republican nominee Mitt Romney in Utah, who in 2016 dismissed Trump as “a phony” who was “playing the American public for suckers.”

Trump has offered up 15 endorsements and five statements supporting candidates this year, including the Cox endorsement in California. Some, like Cruz, ultimately went with Trump over Hillary Clinton in 2016, but many expressed serious reservations about him publicly, especially after the release of the “Access Hollywood” tape in which Trump was captured bragging about groping women. In a few races, Trump has followed the playbook he adopted in Alabama’s special Senate race last year and tipped his hat for the mainstream Republican over candidates explicitly claiming to be most like Trump.

“From where I sit, the perspective is about winning elections and protecting our majority in Congress,” said Harmeet Dhillon, California’s national Republican committeewoman.

Under California’s system, the top two finishers advance to the general election irrespective of party affiliation, opening up the possibility of two Democrats — Lt. Gov. Gavin Newsom and former Los Angeles Mayor Antonio Villaraigosa — facing off in November. Dhillon said Republicans fear a statewide swing of 3 to 4 percentage points because of GOP voters staying home if it’s an all-Democratic ballot, which could make it harder to hold on to key Republican congressional seats and in turn risk Republican control of Congress.

“When you look at those stakes, what the president is doing is what’s best for our country,” Dhillon added.

The Cox endorsement came on the heels of Trump throwing his backing to New York Republican Rep. Dan Donovan over former Rep. Michael Grimm in the Staten Island primary that has devolved into a war over who is closer to the president. “Very importantly, @RepDanDonovan will win for the Republicans in November...and his opponent will not,” Trump wrote on Twitter.

But Trump also noted — wrongly — that the incumbent Donovan voted for the Republican tax cuts championed this past December by Trump, a fact seized upon by Grimm, who’s trying to win his old seat back after serving eight months in prison for tax fraud. Grimm’s first TV ad, launched as part of a modest buy on Fox News ahead of New York’s primary later this month, slammed Donovan for opposing bills backed by Trump: “Every time it mattered, Dan Donovan voted against President Trump,” the Grimm ad states.

In the West Virginia primaries last month, Trump rejected former coal executive Don Blankenship, who modeled his insurgent campaign after the president’s and declared himself “Trumpier than Trump.”

The president told West Virginians that Blankenship, who spent a year in prison for safety violations following a deadly explosion, “can’t win” over Democratic Sen. Joe Manchin in the fall. Instead, Trump urged them to vote for either Republican Rep. Evan Jenkins or the primary victor, Attorney General Patrick Morrisey.

Blankenship attributed his loss to Trump’s late intervention in the race.

There are limits to his largesse. Before the Romney endorsement, Trump had encouraged Utah Sen. Orrin Hatch to seek an eighth term while the 84-year-old contemplated retirement, public remarks that were widely perceived as an attempt to thwart Romney’s plans of serving in the Senate.

Trump declined to pick a candidate in the three-person primary for the Republican nomination in the Arizona Senate race between Republican Rep. Martha McSally, former state Sen. Kelli Ward and former Maricopa County Sheriff Joe Arpaio — the first person Trump pardoned as president, on criminal contempt charges surrounding his treatment of people he suspected of being undocumented immigrants.

But with each endorsement Trump risks drawing fire from his vocal stalwarts, whose support he’ll need in 2020.

His choice of Cox for governor of California came at the expense of Travis Allen, a conservative assemblyman who modeled his campaign after the president, even adopting a variation of his slogan: “Make California Great Again.”

Dhillon, the RNC committeewoman from California, said she has donated money to Allen’s campaign and understands the flood of negative reaction to Trump’s endorsement from Allen devotees.

“At the ground level, if you’re a Travis Allen supporter, it looks like the president got conned,” Dhillon said, summarizing their disappointment given Allen’s loyalty to the president. But the risk of splitting the GOP vote was too great not to intervene, she said.

Cox and an aide in April met with Trump administration officials in Washington, as well as with House Majority Leader Kevin McCarthy, according to a person with knowledge of the talks. The White House and McCarthy also discussed the Cox endorsement before Trump ultimately weighed in.

The White House declined to comment.

On May 18, Trump came out for Cox on Twitter, writing, “California finally deserves a great Governor, one who understands borders, crime and lowering taxes. John Cox is the man — he’ll be the best Governor you’ve ever had.”

On Tuesday morning, he offered another message of support, tweeting, “In High Tax, High Crime California, be sure to get out and vote for Republican John Cox for Governor. He will make a BIG difference!”

Cox campaign manager Tim Rosales told POLITICO on Monday that the president wading into the governor’s race provided “a tremendous boost for the campaign” ahead of Tuesday’s primary.

“President Trump is the leader of the Republican Party,” Rosales said. “And his endorsement was a signal to Republicans that John Cox is the leading candidate.”