Donald Trump has been privately questioning whether his vice-president, JD Vance, possesses the political instincts to sustain the MAGA movement and win the presidency in 2028, according to multiple reports. In conversations with aides and allies, Trump has repeatedly asked a pointed question: “Does Vance really have what it takes to go the distance?” before often answering himself with a blunt “I’m not sure.” The president has even conducted informal polls among guests at a White House event in early May, soliciting views on whether Vance or Secretary of State Marco Rubio would make a stronger presidential candidate.

This private scepticism jars with the effusive public praise Trump has heaped on his 41-year-old deputy. During a cabinet meeting this week, the president compared Vance to Eliot Ness, the legendary Prohibition-era federal agent, casting him as a crusader uncovering electoral fraud in Democratic-run states. Yet the mixed signals come as the administration grapples with a defining foreign-policy challenge: the faltering negotiations with Iran. Last Friday, a Situation Room meeting on the talks ended without a clear decision, exposing a rift between Trump’s instinct for a deal and Vance’s more hawkish stance, which aides say has deepened the president’s doubts about his vice-president’s judgement.

Viewed from Washington, Trump’s behaviour fits a long-established pattern of keeping potential rivals off-balance — a management style he honed in business and imported into the White House. Analysts note that by undermining both Vance and Rubio, he preserves his own dominance over the party and avoids anointing a successor prematurely. However, the constant private benchmarking against his own first-term achievements — a recurring theme in the reported conversations — suggests a deeper anxiety about his legacy and the durability of his political project.

In European capitals, the uncertainty over the Republican succession is watched with unease, particularly as the Iran stand-off threatens to escalate. Diplomats fear that a lame-duck president distracted by internal party dynamics may be less predictable in a crisis. Whether Trump ultimately backs Vance or clears the field for Rubio — or another contender — will shape not only the 2028 race but also the policy trajectory of his final years in office. For now, the question of who can “go the distance” remains open, with the vice-president’s future tied as much to developments in the Gulf as to the whims of a famously capricious boss.