Any lingering doubts about Donald Trump’s primacy in the Republican Party have been settled in recent weeks by the parade of petitioners he has welcomed to his Florida social club.

The party chairwoman, the top two House Republicans, the senior senator from South Carolina and a coterie of other former aides and advisers have all made appearances at Mar-a-Lago, offering their counsel and seeking the favor of a former president who many believe controls the short-term fortunes of GOP candidates up and down the ballot — and has made it clear he plans to use that power.

Over meals and many Diet Cokes, Trump has already started building his post-White House political operation and cementing his role as the party’s de facto leader. He has begun to formalize a structure of political advisers around him and made plans to start a new super PAC — capable of raising donations of any size — to support candidates he favors. His team is looking to formalize a process for vetting endorsement prospects, assessing what candidates have said and done for Trump in the past.

He has also discussed drafting a new “America First” agenda — like the 1994 “Contract with America,” but focused on issues such as border security and trade — to steer the party’s direction, according to Sen. Lindsey O. Graham (R-S.C.).

“He is going to be very involved,” Graham said.

It’s not just about shaping the GOP from the sidelines. Trump is keenly focused on his long-term political comeback, quizzing allies about how to launch a 2024 bid and who his most formidable challengers would be, advisers said.

President Trump left a legacy of disillusionment and despondency across federal agencies. The Post's Lisa Rein and Tom Hamburger analyze Trump's lasting impact (Zach Purser Brown/The Washington Post)

To the relief of party strategists, the former president has abandoned for now talk of starting a third party, according to several people, who, like others interviewed for this story, spoke on the condition of anonymity to describe private conversations.

He has begun intervening to pick favorites in GOP primaries, endorsing on Friday a former aide challenging a House member who voted for his impeachment. But he is not planning to go up against every Republican who defied him, they said. “What’s the point of a civil war in a party you basically control?” joked one Republican operative close to Trump.

A Trump spokesman did not respond to requests for comment.

Trump’s dominance of the GOP will be reinforced Sunday, when he addresses the Conservative Political Action Conference in Orlando, his first major political speech since leaving the White House. In a pageant scripted to emphasize his importance, he will be one of the last to speak in the three-day gathering, taking the stage right after the announcement of a presidential straw poll that he is widely expected to win.

“He is going to make it clear he’s not going anywhere,” one aide said.

Even after the GOP lost the House, Senate and White House under his watch — and Trump was impeached twice, most recently for his role in inciting a violent insurrection at the U.S. Capitol — his sharpest critics concede that he remains in control of the party and his allies are ascendant.

“It’s Donald Trump’s party. It’s the party of [Rep.] Marjorie Taylor Greene,” said Sarah Longwell, a GOP strategist who founded Republican Voters Against Trump. “We are maybe 10 percent. Trump needed to be thoroughly repudiated. Only then could you have a fight for the soul of the Republican Party. That didn’t happen.”

Trump’s new life, as a king in his own domain, in many ways resembles the life he led before running for president, full of meetings and phone calls focused on figuring out how to grow his power and prestige. His preferred tables at the Mar-a-Lago Club and his nearby golf course are cordoned off by ropes, and the other diners typically give him a standing ovation when he comes and leaves, according to four people who have been present. He appears generally in better spirits than many remember from the final year in the White House, they said.

On a recent evening, Trump — who continues not to wear a mask, despite the pandemic — walked around the dining room of his golf club during a buffet-style dinner and handed out cash bills to the employees in the restaurant, according to a person who was present.

“He likes exactly where he’s at right now. People are calling him. People are seeking his endorsement. While I was there, he had like 10 people call and want his endorsement,” said Graham, who spent last weekend at Mar-a-Lago, where he and Trump discussed drafting a new America First agenda.

Republicans have told Trump that it is in his own self-interest to use his influence to help the party in the 2022 midterms, a message they said appears to resonate with him.

“If we do well in 2022, that’s good for his brand. That’s going to help the Trump brand,” Graham said of the message he and other Republicans have been bringing to Florida. “I told him that several times.”

Still, by all accounts, Trump remains furious at a few he believes betrayed him from within during his attempt to overturn the election results — Rep. Liz Cheney (R-Wyo.), Georgia Gov. Brian Kemp (R) and Senate Minority Leader Mitch McConnell (R-Ky.) all come up frequently, sometimes multiple times a day, according to people who speak to him.

Former president Donald Trump slammed Senate Minority Leader Mitch McConnell on Feb. 16, days after the Senate acquitted him in his second impeachment trial. (Reuters)

That desire for revenge worries GOP officials. On Friday, the former president made his first endorsement against an incumbent House Republican, backing a former White House aide, Max Miller, against Rep. Anthony Gonzalez (R-Ohio), a former NFL wide receiver who voted for impeachment. Gonzalez’s district, where Trump won nearly 57 percent of the vote, is considered relatively safe for Republicans in 2022.

“Current Rep. Anthony Gonzalez should not be representing the people of the 16th district because he does not represent their interest or their heart,” Trump said in a statement.

Gonzalez declined to comment.

Trump also recently called Jane Timken, a former chairwoman of the Ohio Republican Party who has aligned herself firmly with Trump, and told her he would endorse her bid to replace retiring Sen. Rob Portman, according to a person familiar with the call. Another candidate in that race, former state treasurer Josh Mandel, has previously called himself “President Trump’s number-one ally in Ohio.” Timken did not immediately respond to a request for comment.

Trump still tells visitors that the election was “stolen” from him but now claims it is because Democrats changed the rules around absentee and vote by mail — and talks less about false allegations involving voting machines made by Dominion, which has been suing his allies. In recent weeks, he has polled advisers on whether he should continue to speak publicly about the last election. Most are urging him to move on.

His shift away from some of the fantastical conspiracy theories he once encouraged has been a comfort to party strategists in recent weeks as Republicans in Washington try to plan a takeover of the House and Senate and win back some of the voters Trump repulsed in 2020. Few are willing to guess whether he will stick by it in the months ahead.

“Generating Republican majorities in the House and Senate is a much better look and feel for a former president than revenge and retribution,” said Kellyanne Conway, Trump’s former campaign manager and senior White House adviser, who has remained in touch with him. “President Trump knows that his impact can be broader and deeper than a myopic focus on the handful of members who voted to impeach him.”

Graham said he told the former president that his personal behavior and his handling of the coronavirus pandemic had damaged him, but that he could repair his standing with policy fights on topics such as immigration.

Trump’s CPAC speech — written by former White House speechwriter Stephen Miller, communications adviser Jason Miller and others, according to advisers — is expected to be a slashing jeremiad against Biden, particularly on immigration. “It will be immigration, one, two and three,” the aide said. Trump is also planning to take credit for the creation of coronavirus vaccines, call for schools to reopen in person across the country and is likely to attack Republicans he views as disloyal, such as Cheney and Sen. Mitt Romney of Utah, and potentially McConnell, an aide said.

He is expected to draw a rapturous reception from the crowd. As they await his arrival, attendees have been posing with a golden Trump statue. Some are carting his now-deleted tweets, bound into books.

“You are going to see a speech on Sunday that talks not only about the beginning but what the future may look like,” Trump’s former chief of staff Mark Meadows said in a recent appearance on Fox News. “What we will see on Sunday is we will see the start of planning for the next administration, and I can tell you the people that are on the top of that list [to win in 2024], all of them have Trump as their last name.”

Some lawmakers said former president Donald Trump’s political future was over on Feb. 14, one day after the Senate acquitted him for the second time in a year. (JM Rieger/The Washington Post)

As is his habit, Trump arranged his appearance at the event himself — reaching out directly to Matt Schlapp, who is running the conference. “He just picked up the phone and called me,” Schlapp said in an interview. “That’s how the man does it.”

Beyond Sunday’s speech and a planned appearance at a Republican National Committee donor retreat in Palm Beach in April, Trump has not yet filled a public schedule. But advisers say they expect him to remain active and appear far more often on television.

The planning is being handled by a familiar network of advisers, who have decided for the moment to leave past feuds and bad blood from the last campaign behind to support the former president. On Thursday, he met with his first 2020 campaign manager, Brad Parscale and the man who replaced him, Bill Stepien, along with Justin Clark, a deputy campaign manager for Trump’s 2020 effort.

Parscale is taking the lead on data and digital efforts, Stepien is advising on endorsements and Clark is working on political and legal issues.

Corey Lewandowski, his 2016 campaign manager, is set to be involved in a new super PAC Trump is expecting to launch as a companion to his Save America leadership PAC. While the latter still has a war chest of millions of dollars given by donors to fight alleged election fraud, Trump has been dissatisfied that the PAC’s legal structure only allows backers to give up to $5,000.

“He’s not really into the first PAC,” a person close to him said. “It has a limit on how much money you can get.”

Trump plans to spend much of the summer at his Bedminster, N.J., country club, and his travel schedule is likely to ramp up later in the year. Miller is managing the communications effort and former White House deputy chief of staff Dan Scavino, who has an office outside Trump’s own private office in the former bridal suite at Mar-a-Lago, is handling social media and other tasks.

Most candidate endorsements are not expected for months, a person involved in the process said.

While he plots his possible return to office, Trump has continued to nurse grudges. There has been discussion of mounting a primary challenge against Sen. Lisa Murkowski (R-Alaska), who voted for impeachment, which many advisers see as a difficult challenge, given her roots in the state and history of winning office without Republican support.

He has dispirited some allies, including former senator David Perdue of Georgia, who left a recent visit to Mar-a-Lago increasingly convinced Trump would make the climate difficult for Republicans in 2022, a person close to him said.

Trump has also complained in recent weeks that RNC Chairwoman Ronna McDaniel is vowing to stay neutral in the 2024 race, wanting the party to throw its support behind him, people who have talked to him said. But the two recently had a warm dinner, according to people familiar with their meeting. Both House Minority Leader Kevin McCarthy (R-Calif.) and Minority Whip Steve Scalise (R-La.) have also had friendly meetings with Trump.

The former president has told advisers that while others are pushing for him to be back on social media, he is “okay taking a break for now,” according to one person who recently saw him. “My numbers have gone up without Twitter,” he has told dining companions, not offering any proof.

He has focused less on a presidential library and other legacy efforts, instead plotting a possible 2024 comeback, people close to him say.

His son Donald Trump Jr. has taken a larger role in the political operation, with son-in-law Jared Kushner receding as an informal chief of staff. Trump has remarked to others that Kushner is a “smart kid,” but said he doesn’t know as much about politics as he believed he did, a person who spoke to Trump recently said.

The question of whether he launches a campaign in 2024 remains open among those close to him, even as Trump is clearly maneuvering to give himself an option. One longtime adviser noted that the ultimate decision was likely to be shaped by external factors.

Trump’s decision to jump into politics was spurred in part by the mocking he endured from President Barack Obama before a crowd at the 2011 White House correspondents’ dinner, this person said.

“If he is left alone, he may or may not run again. If they keep on attacking him, he will get more involved,” the adviser said. “If he is getting attacked, he is going to attack back.”

David Weigel contributed to this report.