A quiet but intensifying rivalry between Secretary of State Marco Rubio and Vice President JD Vance is taking shape inside the Republican Party, with speculation growing about which of the two men is best positioned to carry President Donald Trump’s movement forward after 2028.

JD Vance has long been viewed as the heir apparent to Trump’s MAGA coalition, and he remains the clear frontrunner in informal surveys of Republican voters and donors, having finished first at the CPAC presidential straw poll earlier this year with 53% of the vote.

Rubio, who finished second at the same poll with 35%, has seen his profile rise sharply, driven in large part by his prominent role managing the United States’ response to the Iran conflict that began in February and his high-visibility appearances standing in as White House press secretary while Karoline Leavitt was on maternity leave.

A video clip from one of those press briefings, in which Rubio answered a question from a Christian television network with a visionary tone, spread rapidly online after Elon Musk shared it, with some Republican strategists immediately comparing it to the kind of content associated with presidential campaign rollouts.

GOP strategist Josh Holmes said on the conservative Ruthless podcast: “Are we going to pretend like that’s not a presidential candidate?”

Rubio’s social media team reportedly edited the clip with dramatic music and imagery of Trump and Ronald Reagan, sharpening its campaign-style feel, though the White House issued a statement praising Rubio without directly addressing the 2028 speculation.

Vance, meanwhile, has worked to maintain his positioning through substantive policy work, reportedly helping lead Iran peace negotiations in Pakistan and overseeing a high-profile task force targeting fraud in federal programmes.

He also travelled to Iowa, historically an early primary bellwether, to support a Republican congressional candidate, a trip widely read as groundwork for a future presidential run.

Trump has declined to publicly endorse either man, while reportedly telling Mar-a-Lago donors that both Rubio and Vance are among his top choices as successors.

Rubio himself told Vanity Fair that if Vance runs, he would be the nominee and Rubio would be among the first to support him, a signal of deference that some Republican observers believe is itself a calculated positioning move ahead of 2028.