AFTER Marco Rubio stood down as Speaker of the Florida legislature, he taught classes on the 2008 presidential election, among other things, at Florida International University. “He was fascinated by Barack Obama’s campaign,” says Dario Moreno, a political scientist who also taught there. “He thinks that changes to the economy, generational changes, mean that people are less attached to political parties now and that political realignments can happen more quickly.”

This is a thesis that the Republican primaries ought to test. Mr Rubio, now a senator, joined the fray with a stirring speech in Miami on April 13th. He casts himself as a candidate of change, not only of generation (he is only 43) but also of ideas. Republican presidential wannabes divide into two camps: those who think the party can win by sticking to its guns and those who think it needs to broaden its appeal. The first group includes Scott Walker, the governor of Wisconsin, Ted Cruz, a Texan senator, Mike Huckabee, a governor turned TV host, and a few others. The second group currently consists of Rand Paul, a senator from Kentucky, Jeb Bush, a former governor of Florida and Senator Rubio. Rick Perry and Chris Christie, one a former governor and the other a current one, have yet to commit to either side.

The idea that a Republican could win without becoming more appealing to minority voters was disproved in 2012. Mitt Romney ran up a record score with non-Hispanic white voters, yet still lost. Both Mr Romney and John McCain, the party’s nominee in 2008, would have been president if they had faced the same (largely lily-white) electorate as Ronald Reagan did in 1980, says Whit Ayres, a Republican pollster. And Hillary Clinton, the probable Democratic nominee, is unlikely to do as badly with white voters as Mr Obama did.

To win, a Republican candidate will have to appeal to more non-whites. Mr Rubio, the son of humble Cuban émigrés, won 55% of the Hispanic vote in Florida in 2010. (Mr Romney in 2012 won just 27% nationally and 39% in Florida.) Turnout among non-whites will be higher in a presidential year than it was in 2010. But Mr Rubio has already begun his pitch. “En este pais, ustedes van a poder lograr todas las cosas que nosotros no pudimos,” he said at the campaign launch, quoting his father. “In this country, you will be able to achieve all the things we never could.”

No candidate can be too bold faced with the party’s primary voters, a group dominated by fired-up conservatives. But Mr Rubio is more willing than most to tell his party uncomfortable truths. His first act as a candidate was to sit for an interview on Fox News in which he defended, with caveats, immigration reform and government safety nets. By the standards of today’s Republican Party, this is bold stuff. It might help him in a general election: early polls, for what they are worth, suggest that some voters like it (see chart).

Mr Rubio talks about the working poor, a subject many Republicans avoid in case it leads to a debate about inequality. As a senator he has put forward a list of proposals that blend conservative orthodoxies like repealing Obamacare with some more surprising policies. These include extending tax credits for unmarried workers to boost the wages of struggling men, and more modest cuts to income tax than those favoured by many other Republicans. In 2013 he backed the Senate’s comprehensive immigration bill, though he later disowned this vote. His initial boldness made him a target for his own side: at one point fabricated stories circulated claiming that the bill would give free mobile phones (dubbed “Marcophones”) to people on the Mexican side of the border. Since joining the Senate Foreign Affairs Committee he has taken predictable positions on foreign policy, opposing the president at every turn. His instincts are hawkish: defence and military veterans are the two areas protected in the spending plans he has sketched out, and like Hillary Clinton he was an early advocate of arming rebel groups in Syria. He argues against normalising relations with Cuba (which the White House said it would remove from a list of state sponsors of terrorism on April 14th), on the ground that this will legitimise a dictatorship. Most Cuban Americans arrived after 1980 and disagree: they have no desire to see their relatives on the island suffer under sanctions.