Former President Donald Trump’s coronation next week at the Republican National Convention is expected to come after he anoints not only his running mate but the early favorite to be the MAGA standard-bearer in 2028.

Mr. Trump has been open about some of the people under consideration but has kept his cards close to the vest on a decision that could have a massive domino effect on national politics for years.

“President Trump’s selection of a running mate is more important for two reasons: First, it will provide a contrast to Kamala Harris, who is truly a disaster,” said Charlie Gerow, a delegate to the Republican National Convention from Pennsylvania. “And Second, the vice president will likely be the next president of the United States after 2028.”

Typically, the fuss and furor over who wins the No. 2 slot dies down after the media blitz that follows the much-ballyhooed announcement — and the spotlight turns back to the headliners.

But this year is shaping up to be different.

President Biden’s failure to stamp out concerns about whether he is cognitively all there has stoked speculation that Vice President Kamala Harris — or another prominent Democrat — will be called out of the bullpen to replace him.

Mr. Trump, if he wins, will be limited to a single four-year term and will be forced to pass the baton. If he loses, father time could damper any further political ambitions.

The scenarios leave his loyal followers looking to him for guidance on who is the MAGA heir apparent though some Republicans hope he picks someone cut from a more traditional mold.

Mr. Trump has confirmed that North Dakota Gov. Doug Burgum and Sens. J.D. Vance of Ohio and Marco Rubio of Florida are on the shortlist.

Sen. Tim Scott of South Carolina and former Housing and Urban Development Secretary Ben Carson are thought to be still in the mix.

“We have a lot of good people,” Mr. Trump said on FOX News’ Hannity. “As they call it, we have a great bench in the Republican Party.”

But he has sent mixed messages about where he is in the decision-making process and when he will deliver the news.

Last month, he said his mind was made up. This week, he said he is still mulling his options, suggesting he was waiting to see whether Mr. Biden would step aside.

“I haven’t made a final decision, but I have some ideas as to where we’re going and a little bit we wanted to see what they’re doing, to be honest, because it might make a difference,” he said.

The announcement, meanwhile, could come over the coming days or after the Republican National Convention kicks off in Milwaukee on Monday.

“I’d love to do it during the convention,” Mr. Trump said.

All the coyness has heightened the anticipation around a final decision that could have a domino effect on national politics for years to come.

That extends to members of the Republican National Committee who have never been thrilled about Mr. Trump’s takeover of the party. They hope to see a vice presidential nominee who can appeal to the populist tendencies of the MAGA movement without selling out conservative principles.

Here’s the shortlist:

J.D. Vance

Mr. Vance has had one of the most dramatic public evolutions on Mr. Trump — jumping from being a self-declared “Never Trump guy” in 2016 to one of the former president’s fiercest allies and someone who is most familiar with the DNA of the MAGA movement.

Mr. Vance has flashed his smarts and political skills as a surrogate for Mr. Trump on the television talk show circuit. He has welcomed clashes with the media, attacked Mr. Biden’s policy vision and sang Mr. Trump’s praises.

Elected in 2022, the 39-year-old Vance is a former Marine and authored the best-selling “Hillbilly Elegy.” He graduated from Yale Law School where he met his wife, with whom he has three children.

That biography could help strengthen Mr. Trump’s appeal across the Rust Belt states — particularly Michigan, Pennsylvania and Wisconsin. His understanding of the MAGA movement makes him a natural successor to Mr. Trump.

Indeed, Mr. Vance embodies Trump’s populist streak. He questions the taxpayer dollars being sent to help Ukraine defend itself in its war with Russia and embraces Mr. Trump’s hardnosed approach to securing the US-Mexico border.

“Trump can do the job. Biden can’t,” Mr. Vance said in a recent interview.

Mr. Vance is open about his desire to be vice president but has said he is honored to serve in the Senate and to help Mr. Trump in any way possible.

“Let’s get back to success,” he said. “Let’s get back to peace and prosperity.”

Marco Rubio

The veep chatter around Mr. Rubio has been on the rise for months, and some political oddsmakers now rank him as the favorite for the job.

Mr. Rubio has long been considered among the party’s most natural talents since he rode the Tea Party wave to victory in the 2010 elections.

Mr. Rubio clashed with Mr. Trump in the 2016 GOP primary when he ran as a military hawk and Mr. Trump nicknamed him “Little Marco.”

Since then he has welcomed the chance to be a go-to voice on national security and global affairs as a member of the Senate Foreign Relations and Intelligence committees.

Political analysts say the 53-year-old son of Cuban immigrants could help further strengthen Mr. Trump’s hand with Hispanic voters and ease concerns among GOP primary voters who backed Nikki Haley’s more robust foreign policy vision.

“Donald Trump’s running on common sense, on restoring common sense versus the lunacy of the last four years in the far left and the shadow government that now is running our country with Joe Biden as its figurehead,” Mr. Rubio said Sunday on CNN. “That’s what he’s running against.”

“All I care about at this point and what I care about the most is that we can’t afford another four years like the last four,” he said. “And I’m willing to help in any way I can.”

There is a catch with Mr. Rubio. He would likely have to move out of Florida if selected because the Constitution states that electoral college voters are barred from voting for president and vice president from the same state.

Doug Burgum

Mr. Burgum has gone from being a little-known two-term governor from North Dakota running for the GOP presidential nomination to one of Mr. Trump’s more trusted advisors.

The 67-year-old’s governing experience outside Washington and low-wattage style could help balance Mr. Trump’s boisterous behavior and boost the ticket’s appeal with mild-mannered moderate, independent-minded voters in battleground states.

Mr. Burgum has strong ties with major players in the energy industry after governing in a state that has experienced an oil boom.

“If you believe in liquid fuels, you’re on Team USA,” Mr. Burgum said recently on FOX Business Network. “If you believe in the whole EV, then you’re on team China because you can’t have an EV car industry in this country without buying batteries from China.”

“The climate extremists who are driving policy in Biden’s administration are saying, ‘Hey, let’s just become dependent for our transportation future on China.’”

While Mr. Burgum’s lack of pizazz will increase the chances the spotlight stays on Mr. Trump, it also makes him, arguably, the most boring possible pick.

• Seth McLaughlin can be reached at smclaughlin@washingtontimes.com.