Last Thursday’s referendum gave Britons an opportunity to kick the political establishment, and they took it. Great Britain will now exit the European Union. The price of ‘Brexit’ is economic and cultural stagnation – an end to the unfettered freedom to trade, hire, work, live and travel across Europe.

Nobody really expected Brexit to happen. As a British foreign student, everything I heard from my family, friends, the pollsters, the financial and betting markets, even senior figures in the Leave campaign as voting closed, confidently predicted a Remain victory. But everyone was wrong.

My American colleagues should take note: Brexit shows that the politics of division and ignorance can win. Leave won by harnessing and cultivating anti-immigration and anti-establishment disenchantment and intolerance – sentiments which may sound familiar to an American ear.

America has been derided for the rise of The Donald. Across the Atlantic, and in many cosmopolitan parts of the United States, American politics has long been baffling – your guns, homelessness, gaping inequality – but Trump seemed preposterous. Yet far-right, Trump-like politics have been doing dangerously well in other European countries like France. And then came Brexit.

But Britain’s vote is past, and America’s is still to come. There are two things progressive Bruins can learn from progressive Britons’ mistakes in the referendum:

First, vote. Young Britons aged 18-24 voted 73% for Remain; but Leave carried it among people over 45. The problem is that old people vote, and young people don’t. Areas with younger populations had lower turnout in the referendum. Likewise, in the U.S. 2012 Presidential election, turnout was 38% among the 18-24 demographic, versus 70% among people over 65. If you want different things from your government than your grandparents, go out and vote for it.

That said, frankly, in safely Democratic California, your vote doesn’t count for much. While voting is a start, it may not be enough.

Which leads to my second point: Campaign not where it is easy, but where it is hard.

Support for Remain was so overwhelming in the echo chambers of the young and progressive on Facebook and in London that Leave-ers seemed not to exist. This complacency among many otherwise politically engaged people meant that the case for Remain never made it to the far-flung towns and villages of England.

As inconceivable as it may seem on campus, Trump voters exist. But more importantly, for practical purposes, swing voters exist. You can make a real difference by reaching out to swing voters in swing states. Leafleting on Bruin Walk is wasted effort – join a phone bank and make calls to Florida instead.

Because Brexit shows that Trump can win.

Richard Stockwell is a first-year graduate student studying linguistics.