Viking rock and whole pigs roasting on spits drew thousands of Swedes to a festival hosted by nationalists poised to deliver their country’s biggest political upheaval in a century.

The Sweden Democrats have been led since 2005 by a clean-cut and bespectacled man, Jimmie Akesson. He’s gentrified a party that traces its roots back to the country’s neo-Nazi, white supremacist fringe. Some polls now show the group may become the biggest in Sweden’s parliament after general elections on Sept. 9. Such an outcome would end 100 years of Social Democratic dominance.

In Akesson’s hometown of Solvesborg, large crowds cheered as he laid out the party’s vision for drastic cuts in immigration. His agenda is part of a global wave of nationalist and anti-establishment sentiment that has followed the 2008 financial crisis, with the election of Donald Trump in the U.S. and Britain’s vote to leave the European Union standing out as the starkest examples of the new world order.

For Sweden, a tipping point was the refugee crisis of 2015. Over the past decades, the once homogeneous nation of 10 million people has been transformed, with 18 percent of the population now born outside the country.

Most Swedes profess to have a positive view toward immigration. But voters have become more comfortable voicing misgivings after their country accepted as many as 600,000 refugees over the past five years.

At his party’s festival, Akesson revved up the crowd by slamming the establishment’s failures. T-shirts calling for a Swexit, or an exit from the E.U., were exchanged as bands played nationalist tunes.

Ted Lorentsson, a retiree from the island of Tjorn, said he’s an enthusiastic backer of the Sweden Democrats. “I think they want to improve elderly care, health care, child care,” he said. “Bring back the old Sweden.” But he also acknowledges his view has led to disagreement within his family as his daughter recoils at what she feels is the “Hitler”-like rhetoric.

Other supporters say they’re frustrated that Sweden’s economic boom over recent years has failed to translate into gains in welfare and other services. “Trains and hospitals don’t work, but immigration continues,” said Roger Mathson, a retired vegetable oil factory worker.

“I’m not a racist, but I’m a nationalist,” he said. “I don’t like seeing the town square full of niqab-clad ladies and people fighting with each other.”

The Social Democrat-led government of Prime Minister Stefan Lofven has overseen economic growth rates exceeding 3 percent, in part fueled by immigration. But at the same time, Swedes have had to wait longer to get access to welfare staples like hospital care. Meanwhile, crime rates have risen with more gang-related shootings, reported rapes and vandalism. On Monday night, scores of cars were set on fire in Gothenburg, in what the police say may have been a coordinated attack.

Pia Persson, a 60-year-old who lives in Kristianstad and works at Absolut Vodka, says she’s voting for the Sweden Democrats after feeling neglected by the current government. That includes waiting too long at her doctor’s office, where Persson says she’s sometimes the “only Swede.”

“I think you need to start seeing the whole picture in Sweden and save the original Swedish population,” she said.

Sebastian Svensson, an engineer who works at a surveyor’s office, says he’s backed the center-right opposition party the Moderates in the past. But he’s had enough.

“It would be OK to have very high taxes if we had the best health care in Europe, for example,” he said. “But we don’t.”