Marco Rubio is the Republicans’ best hope for the White House – and the future

Rubio’s youth and optimism contrasts with the Republican line-up of grouchy blokes and a solitary sharp-edged woman

Marco Rubio, pictured on stage with family members, delivered a polished performance in which he took on Jeb Bush (Getty)

Almost from the moment he became a senator four years ago, Marco Rubio has been marked out as a potential Republican saviour. This savvy son of Cuban immigrants is seen as the man who could win back the White House from the Democrats, with the ability to create a new constituency for a party that struggles to accept the changing demographics of American politics. Now we will see if he is worthy of those great expectations.

Last week, he used the latest Republican debate to shrug off an attack by Jeb Bush, his key rival on the party’s “moderate” wing. It was deftly done, subtly underlining comparisons between Barack Obama, the first black president, and the 44-year-old from Florida seeking to be the first Latino occupant of the White House. Few observers could avoid the striking contrast between Bush, whose father and brother were both presidents, and his one-time protegé whose mother cleaned hotel rooms as a migrant maid.

There are 12 long months to go before voters finally get to choose the 45th president of the United States. But already the smoke is clearing slightly on the two campaign battlefronts. Hillary Clinton has had a superb couple of weeks, seeing off any threat of Vice-President Joe Biden entering the race with a strong performance in her side’s debate, then defying intense questioning from conservative critics over the private email issue dogging her for months.

Yet her biggest challenge is presenting herself as the candidate for change after eight years of a Democrat president – a curious position for someone who would be the first female US president. But aided by a smart team of advisers, she has shown herself surprisingly adroit at adapting to the shifting pattern of politics on the left. And her party has an inbuilt current political advantage that one analyst told me ensures it starts with 246 of the 273 electoral college votes already bagged.

This is what makes the Republican race so fascinating – and so resonant as a warning to conservatives in this country. For the party is engaged in something close to civil war between those who believe they can win by appealing largely to angry, white older voters, who are frustrated by loss of power and the pace of change, and those appreciating the imperative to reach out to younger people, single women and ethnic minorities.

The first camp is represented with alarming clarity by Donald Trump, still riding high in polls as he rails against foreigners, immigrants and elites in Washington and Wall Street.

This could win him the first contest in Iowa, where the fastest-growing demographic is over-90-years-olds. Yet one rival thinks Trump will pull out before Iowa, reluctant to risk a loser’s speech while claiming to have changed the political landscape. Regardless, the donors and party establishment will rally around whichever mainstream candidate looks most likely to defeat the insurgents.

This was seen as Bush, the man with twice as much money as any other candidate. But more and more that candidate looks like Rubio, although polling still puts him in single figures. His youth and optimism contrast with the Republican line-up of grouchy blokes and a solitary sharp-edged woman; he also looks very different from Clinton, given his age and heritage. The big question, especially given his flip-flopping on immigration, is whether he will attempt to reposition the Republicans if nominated.

Last year I joined a small dinner with Rubio, who wanted to discuss with Tory modernisers the shared challenges facing British and American parties of the right. We tend to see Republicans through the prism of guns, religion and abortion, but his focus was on how to connect with fast-growing chunks of the electorate as he asked all about David Cameron’s makeover of the Conservatives. I found him thoughtful on domestic issues, disappointingly hawkish on foreign policy.

If the Republicans have any hope of gaining the White House, they must accept the changing American electorate. Their support base – older, suburban and increasingly white – is shrinking. Right-wing populism and anti-immigration zealotry lead to a dead end; they must broaden their appeal to minority voters to survive. Mitt Romney won six out of 10 white votes in 2012, enough to triumph without a single ethnic minority vote had he faced the same electorate as Ronald Reagan. Likewise for John McCain, the nominee in 2008.

This is the prize for Rubio if he wins the nomination and strikes out in a new direction. There is a clear risk, since those angry voters flocking to hear Trump speak might stay at home on polling day rather than endorse another “establishment” figure. But it is hard to see any alternative strategy leading to success – even if Clinton reverts to her cautious former style of triangulation and trouble avoidance. It should not be forgotten David Cameron’s surprise majority involved the party’s biggest share of ethnic minority support.

The US election shows the shifting dynamics of Western democracies, increasingly divided between parties comfortable with modernity and those that try to fight it. The fissures are less between left and right than between isolation and integration, exclusion and inclusion, anger and optimism, hate and hope. This is why the fight should flash warning signs not just to the British right, but to a Labour Party retreating into its comfort zone. Jeremy Corbyn should watch the Republican race just as closely as the Conservatives.