POWERFUL, impressive and built around antique technology, a Harley-Davidson motorcycle is a complicated symbol of national pride. Add a hefty dose of conservative politics and it is no surprise that clouds of nostalgia hung around today’s first annual Roast and Ride—a barbecue- and Harley-themed patriotic festival organised by Iowa’s freshman senator, Joni Ernst, as a salute to military veterans and speechifying contest for 2016 presidential hopefuls. The senator, a lieutenant colonel in the Iowa national guard who served in Iraq, led a parade of over 300 vast, rumbling motorcycles from Des Moines to a country showground in Boone, in the heart of the state which will, early next year, hold the first nominating contest of the presidential season. A lot of the bikers were military veterans, and the emotional legacies of war were on startlingly raw display as they set off. Riders wore t-shirts declaring “Freedom isn’t free”, or—in one case—comparing President Barack Obama to Adolf Hitler, while their baseball caps and jacket patches told of the units and campaigns in which they had served. They wrapped Senator Ernst, a small-framed but commanding figure, in bear-hugs, and thanked each other for their service. The mood blended anger, defiance, sadness and pride.

Governor Scott Walker of Wisconsin (pictured), a Harley rider of some years’ standing, was the only presidential hopeful to join Ms Ernst at the head of the ride (he is expected to announce his formal candidacy in a few weeks). A slight, confident, impeccably polite figure, he seemed at once part of the group—for lots of the Republicans there like his conservative record a lot—and not one of the crowd. He is not a military veteran. He seemed almost a bit uncool next to Ms Ernst, with his Harley branded jacket and gloves (he proudly showed reporters his Harley-branded wallet) and clear safety goggles. He could have been the enthusiastic, popular pastor of a local megachurch.

The day’s themes of patriotism and thanksgiving dominated the speeches given by the seven Republican presidential hopefuls who spoke. This made for a powerful sort of day, but a problematic one for the Republican field. For too many speeches amounted to a lament for the past.

As is the case in all rich western countries, the dominant narrative in American politics concerns the squeezing of the middle class, anxiety about the future and arguments about the sustainability of public finances. The speakers at the Roast and Ride lamented the vanishing of the well-paid jobs that once powered the middle classes to prosperity, and sounded the alarm about a world in chaos, which they pinned on the feckless foreign policy of the current president.

But if all heaped scorn on Mr Obama, and were cheered for it, there was a striking generational gap on display. For six of the presidential hopefuls in Boone essentially painted a picture of an America that had been mighty, should be mighty and yet was somehow lost. Their explanations essentially accused Mr Obama and the Democrats of treachery—of betraying the values and codes of morality that make America great, in part because, in their telling, Mr Obama does not really believe that America is an exceptional nation.

Some of these laments made for potent oratory. Rick Perry, the former three-term governor of Texas who crashed out of the 2012 presidential race when he forgot which bits of the government he wanted to abolish at a TV debate, is on the campaign trail again this year. He is much better-prepared, and there is a swaggering dash to the way that he panders to conservative activists. Mr Perry is a biker, but did not join Ms Ernst and Mr Walker in their ride. Indeed, this puzzled Mr Walker briefly, who could be heard expressing surprise as the ride began that “Rick Perry isn’t riding.” Alas for Mr Walker, Mr Perry was not only riding to Boone in his own cavalcade, he was riding from a town called Perry, Iowa, on a Harley belonging to a wounded veteran, accompanied by decorated war heroes, to raise funds for a charity that gives puppies to military veterans.

In his speech to the audience of Iowan conservatives, Mr Perry’s loudest applause came when he recalled confronting Mr Obama during a border-crossing crisis in the summer of 2014, and telling him: “Mr President, if you do not protect the border, Texas will.” An extraordinary country was being let down, but could be put right with a few good policy changes and a change of leadership, Mr Perry told the crowd. America had made it through the Civil War, two world wars and Jimmy Carter. It could make it through the Obama era.

Mr Perry is 65 years old, while Mr Walker is 47. But the two governors sounded rather similar in their wistful recollections of modest childhoods marked by cheerful, hard-working, up-by-the-bootstraps small town thrift. Mr Walker was the undoubted star of the day even before he arrived. His speech was well-received, but it was a disappointment. He talked of an American Dream led astray, and set up a straw man attack on Mr Obama and the likely Democratic nominee, Hillary Clinton, saying that to listen to them, the measure of success in America was “how many people are dependent on government.” But in his own childhood in small town America, nobody said or wrote in their high school yearbooks that they wanted to grow up to be dependent on the government, Mr Walker said. The great thing about America, he went on, was that it offered equality of opportunity, even if outcomes were up to individuals. America is one of the few countries left in the world where it doesn’t matter what class you are born into, he declared, and many in the audience, notably the older voters with snowy hair, clapped enthusiastically.

But even in a political speech to activists, that was a riskily glib thing to say. The evidence is overwhelming that American social mobility has stalled in recent decades, and that accidents of birth have come to matter far too much. The great question of the age is how to fix that, and both thoughtful Republicans and Democrats have begun wrestling with competing solutions. Mr Walker simply sweeps that debate aside, and in doing so sounds like a spokesman for an imperfectly-remembered past when the American Dream came easily.

The contrast was startling when Senator Marco Rubio came to talk. The Cuban-American senator from Florida is only three years younger than Mr Walker, but he sounded as if he came from a different generation. The economy has changed in the past 20 years, he told the crowd. There is more global competition and machines can do many of the jobs that once paid good wages to middle class workers. We are living through a moment of transformation such as we have not seen since the Industrial Revolution, Mr Rubio said. Unfortunately, we have all of these leaders that are stuck in the past, he said. He was polite enough to add: “especially on the left”, but his rebuke to some of his Republican rivals was well made.

In part Mr Rubio is defending himself tactically from the charge that America is not ready to hand the White House to another young, eloquent senator (having tried that with a certain Senator Obama from Illinois). But he is right to challenge crowds such as the one in Boone. I like the 20th century, Mr Rubio joked. I was born in the 20th century. But it is time to build a new American century.

Mr Rubio did not ride a very large motorcycle to the Roast and Ride, though Ms Ernst did kindly offer to give him a lift on hers, as a pillion passenger. Good for him. Magnificent beasts though Harleys are, they are symbols of the past: loud, inefficient hunks of nostalgia beloved of Baby Boomers. If the Republicans are wise, they will choose a politician who travels more lightly, eyes fixed on the future.