U.S. President Donald Trump has begun floating a succession lineup in private. On the surface, Vice President JD Vance remains the No. 1 pick, but with the major variable of the Iran war erupting, the current is shifting toward Secretary of State Marco Rubio.
Major outlets including the New York Times (NYT) and the Independent reported on the 10th (local time) that Trump has been repeatedly asking aides and confidants in the Oval Office, at dinner with acquaintances, and in private at the Mar-a-Lago resort, "What do you think? JD or Marco?" Trump reportedly calls the two "kids" and is even considering the possibility of simultaneously backing them as Republican presidential candidates in 2028.
Trump aides drew a line, saying it was "just for fun." But in Washington, the fact that the president himself has placed the two in a direct comparison is being interpreted as a signal that he is asking about the order of succession to power. The dominant analysis is that, before any formal designation, the president is directly putting prospective successors in a comparative frame and stoking an intraparty power struggle.
The turning point when Secretary Rubio began to stand out in the succession picture led by Vice President Vance was the Iran war. On the 5th of this month, Rubio personally appeared in the White House briefing room to explain the Iran war and the Strait of Hormuz crisis. He took tough questions from foreign media himself, mixing Spanish and even Italian, in a scene that was aired at length. Rubio's office repackaged the footage into a short, campaign-style clip with an American patriotic feel and spread it online. The Washington Post described the trend as "Marcomentum."
Secretary Rubio's moves have extended beyond the United States to Europe this month. In the Vatican, Rubio met Pope Leo XIV and presented a crystal football, and he also met Italian Prime Minister Giorgia Meloni. Both had publicly expressed opposition to Trump's decision to strike Iran. A dynamic has formed in which Rubio is patching up diplomatic friction created by Trump. As secretary of state, Rubio has also taken the lead on the agenda ahead of the Trump-Xi Jinping summit on the 14th, publicly pressuring China over its influence on Iran.
Since January, Rubio has led the ouster of Venezuela's Nicolás Maduro and then the pressure campaign on Cuba. He has established himself as the operational commander tasked with strengthening hegemony in the Western Hemisphere within the Trump administration. In a CNN interview, Trump, mentioning the possibility of the Cuban regime's collapse, said he was "thinking of sending Marco there." It was also belatedly revealed that during the security meeting at the White House where Maduro's arrest and the Iran airstrikes were decided, Rubio was by Trump's side, while Vice President Vance participated by video.
Rubio serves as both secretary of state and national security adviser. Online, a meme is trending that he takes on all sorts of posts. Republican pollster Whit Ayres said in an NYT interview that Rubio is "a politician who can appeal to Republicans who agreed with Trump but did not become overly enthusiastic."
By contrast, Vice President Vance, once the leading No. 1 contender, is struggling as he reveals clear limits in a wartime phase. He has been a non-interventionist since his Senate days, criticizing military interventions in Iraq, Afghanistan and Libya. In a 2023 op-ed, he cited "not getting involved in wars" as a factor in the success of Trump's first term. As vice president, he must defend the decision of the president, the commander in chief, but he cannot ignore the antiwar sentiment of the core Make America Great Again (MAGA) base.
Vance has made almost no public comments throughout the Iran war. When a reporter asked, "What advice did you give President Trump about the Iran war?" he avoided answering, saying, "I will not publicly disclose remarks made in a classified meeting." CNN said, "Vance has significantly reduced his social media activity over the past two weeks, and his Iran-related posts have been limited to commemorating the fallen or sharing Trump's remarks."
Instead, Vance is throwing himself into party organization. As finance chair of the Republican National Committee (RNC), he is leading fundraising, and recently he was dispatched to a factory site in Des Moines, Iowa, one of the GOP strongholds, to stump for Rep. Zach Nunn. There, he mentioned two Iowa-born soldiers who were killed in a March Iranian drone attack on a U.S. base in Kuwait and appealed, "We need to make this country worthy of their sacrifice." Mark Short, former chief of staff to former Vice President Mike Pence, told the NYT, "A president expects complete loyalty from a vice president, but in my experience, a president does not look after the vice president's future political success."
On the U.S. prediction market platform Kalshi, Secretary Rubio's probability of winning the 2028 presidential primary jumped from 6% at the start of the year to 19% on May 6. During the same period, Vice President Vance fell from 29.7% to 18%, narrowing the gap between the two to within the margin of error. It is interpreted to mean that Washington lobbyists who manage political money have begun seriously reassessing Secretary Rubio as a strong alternative to replace Vice President Vance.
In traditional public opinion polls of the general public, Vice President Vance still leads. In an Echelon Insights poll, Vance held 42% support in the Republican primary to Rubio's 14%, a wide gap. In the Conservative Political Action Conference (CPAC) straw poll, Vance led 53% to Rubio's 35%. However, Rubio rose from 3% in last year's CPAC poll to 35% this year. In a Pew Research Center survey, 75% of Republican voters viewed Vance favorably, while Rubio's favorability was 64%, and 19% said they had never heard of him. Based on party members, Vance still holds a solid lead in popular recognition.
However, observers say it is still early to predict a full-fledged contest between the two. In a Vanity Fair interview last year, Rubio said, "If JD Vance runs for president, he will be our candidate, and I will be one of the first to support him." The balance of power is expected to swing again depending on the midterm elections in Nov. and whether the Iran war drags on. Political insiders believe that if Republicans perform well in the midterms, Vice President Vance, who oversaw party organization, will firmly establish himself as the true heir to the MAGA movement. But if the prolonged war sends oil prices soaring and rattles the broader economy, the political expense of policy failure is likely to fall squarely on the vice president.