The safe choice for vice-president was not J.D. Vance. He arrived on Donald Trump’s presidential ticket with little political experience and plenty of baggage. During his two years in the Senate some senior colleagues found the Ohio freshman’s strident opposition to Republican policy orthodoxy presumptuous. And more than a few Republican lawmakers and donors still privately acknowledge they would have preferred someone else. Yet the vice-president, the third-youngest in American history, has proved adept at a role that often ends up as a political dead end. And Mr Vance, seen by America’s allies as a divisive figure, is casting himself as a uniter of his party’s fractious factions. He argues that he was uniquely placed to bridge the gap between the “techno-optimist” and “populist right” MAGA tribes.