President Trump has long fancied himself an expert negotiator, so proficient at extracting concessions from opponents that he even wrote a bestseller called “The Art of the Deal.” He promised to renegotiate trade agreements, and his “deal of the century” aimed to solve the Israeli-Arab conflict.

Now, in a post-presidency that has been every bit as unconventional as his time in the Oval Office, Mr. Trump is seemingly embarking on a new pastime. “I’m a gambler,” the Washington Post reports that he told an aide in recent weeks, as he upends the safetyism that usually accompanies political endorsements. 

In Sarah Palin, Mehmet Oz, James David Vance, and Herschel Walker, Mr. Trump has tapped a quartet of candidates for House and Senate who are colorful, unconventional, and disruptive in equal measure. None of them are carbon copies of Donald Trump, but none of them are outside his orbit. 

His longtime political svengali, Roger Stone, tells the New York Times that Mr. Trump is “not bound by the conventional rules of politics.” This election cycle seems designed to put that proposition to the test, even though Mr. Trump is not himself on the ballot.  

These endorsements paint a picture of a political kingpin playing for keeps against an establishment perpetually hedging its bets. The Republican governor of Maryland, Lawrence Hogan, called Mr. Trump’s choices “crazy.” We will see if voters agree.    

In place of the staid calculus that often drives support, Mr. Trump is approaching the task with a different mentality, as he throws support behind more than 100 candidates. In races across the country, the man who famously loves to win is backing candidates who are far from locks.

However, each of these particular four candidates is viable and in supporting them and others a picture is emerging of the new alliances that Mr. Trump is building in hopes of further entrenching his influence. 

The Sun’s Conrad Black, who speaks to Mr. Trump regularly, notes that “the president keeps his own counsel.” Nevertheless, Mr. Black surmises that a man who “translated celebrity into high political office” may be on the alert for others seeking to pull off the same alchemy.      

By gravitating toward candidates with elevated risk and reward profiles, Mr. Trump is betting on the force of his imprimatur to push into office a slate of candidates crafted in his image in advance of his own likely rumored return to electoral politics in 2024. 

Many see Governor Palin’s 2008 bid for vice president as a dry run for Mr. Trump’s own outsider conquest of the Republican field eight years later, with the two mavericks sharing a penchant for candid speech and tossing away the script. 

Sensing this affinity, Ms. Palin was one of Mr. Trump’s earliest high-profile backers, throwing her weight behind the media mogul before the 2016 Iowa caucuses at a time when many Republicans had not yet reconciled to the reality of his electoral strength. 

As Mr. Trump puts it, “Sarah shocked many when she endorsed me very early in 2016, and we won big. Now, it’s my turn.” He called her “tough and smart,” and bestowed upon her his “Complete and Total Endorsement.” Ms. Palin has told the Associated Press she would be open to reprising her VP role, this time on a ticket with Mr. Trump in 2024.  

Ms. Palin will likely need Mr. Trump’s backing, as she enters a crowded primary field swarming with candidates to replace Donald Young, who was the longest serving Republican in congressional history yet who passed away last month. Many Alaskans still look askance at her 2009 gubernatorial resignation. 

Nevertheless, one poll finds Ms. Palin with a five percentage point edge on her nearest competitor for the congressional seat, though others show a dead heat. It is a tight race, and Ms. Palin is far from a sure thing in a state that Mr. Trump won by 10 percentage points in 2020. 

From the Frontier State to the Keystone State, another high-wattage candidate has garnered Mr. Trump’s support as well. Dr. Oz, a cardiothoracic surgeon and daytime television protege of Oprah Winfrey, is joined in a heated battle with a onetime Bridgewater chief executive officer, David McCormick.

The polls show a dead heat in the race to succeed Senator Toomey, who is retiring, with the latest survey giving Dr. Oz 14.4 percent of the vote and Mr. McCormick 14.3 percent. Mr. Trump has waded into this closely contested contest, and not on behalf of the establishment candidate.

Explaining his reasoning, Mr. Trump said “when you’re in television for 18 years, that’s like a poll, that means people like you.” The candidate he previously backed in the race, Sean Parnell, was forced to withdraw after accusations of abuse made by his ex-wife. Mr. Parnell now backs Mr. McCormick.

Mr. Trump’s support for Dr. Oz has occasioned backlash from otherwise supportive quarters. Conservative radio host Erick Erickson tweeted, “it’s like Donald Trump’s staff is sabotaging Trump by convincing him to make the worst possible endorsements.”

A similarly contentious dynamic is unfolding in the Midwest, where yet another unusual candidate has garnered the backing of the 45th President: J.D. Vance, the author of the bestseller “Hillbilly Elegy” and a venture capitalist who has turned his attention to the Senate. 

It is a crowded field, with Mr. Vance vying with a onetime state treasurer, Joshua Mandel, and an investment banker, Michael Gibbons. While polls have Mr. Vance running third, he is Mr. Trump’s choice, even though he acknowledged that “this is not an easy endorsement for me to make.”

Mr. Vance once called Mr. Trump an “idiot,” and a leaked screenshot sent to his college roommate in 2016 shows him speculating that the president might be “America’s Hitler.” Mr. Trump acknowledged that “like some others, J.D. Vance may have said some not so great things about me in the past, but he gets it now.” 

Others who are convinced Mr. Vance “gets it” are an influential group of supporters that include venture capitalist Peter Thiel, broadcaster Tucker Carlson, and Donald Trump Jr. Now the biggest name in Republican politics is planning on campaigning with Mr. Vance.

In the Peachtree State, Mr. Walker, who won the Heisman trophy at the University of Georgia, is generally thought to be the most accomplished college football player of all time. As a professional, he was the centerpiece of the largest football trade in the NFL’s annals, a 1989 blockbuster at which old-timers still shake their heads.

Mr. Walker has now set his sights on politics, but his campaign to represent Georgia in the Senate has not been without fumbles. The most serious of these are accusations from his former wife of “physically abusive and extremely threatening behavior.” A restraining order ensued. Mr. Walker has pointed to a dissociative identity disorder diagnosis as the culprit.

However, he enjoys steadfast backing from Mr. Trump, even as his campaign has been beset by further challenges. He was a no-show for a debate over the weekend, with one rival quipping, “his coaches now have him locked in the basement of the locker room.”

Despite these missteps, the latest polling shows Mr. Walker with a sizable lead over his primary opponents and a slight edge over the Democratic incumbent, Senator Warnock, with whom he will tussle should he matriculate to the general election. 

This will likely temper rather than allay fears among Republicans that in backing Mr. Walker, Mr. Trump is poised to reprise 2020, when control of the Senate slipped Republican fingers.

Mr. Trump’s ambitions to further stamp his brand of politics onto  the House and Senate is far from limited to Ms. Palin, Dr. Oz, Mr. Vance, and Mr. Walker. Also in Georgia, Mr. Trump has come down on the side of Senator Perdue, a marked underdog, rather than Governor Kemp.

Mr. Trump has also signaled support for the current bad boy in Republican politics, Representative Madison Cawthorn. After his comments about “the sexual perversion that goes on in Washington” and reports of orgies and cocaine, the Tar Hell representative was reprimanded by party bigwigs.  

The House minority leader, Representative Kevin McCarthy, said that Mr. Cawthorn, who also faces constitutional disqualification efforts from Democrats, “lost my trust” due to “unbecoming behavior.” President Trump, on the other hand, gave him a coveted speaking slot at one of his rallies.