About a decade ago, a wave of populism crashed across Europe. Reeling from the financial crisis, voters flirted with risky alternatives to mainstream parties, threatening tumult in the continent's usually stable politics. It was an unsettling time for Europe's leaders. But pundits assured them that the risk of a far-right takeover was overblown. Robust electoral systems, not-so-distant memories of dictatorships and weak support among wealthier voters, they believed, put hard ceilings on the insurgents' support. Today it's clear their confidence was mistaken. Far-right parties have kept piling on votes, established themselves in European institutions, reversed key tenets of the green transition and forced tougher border policies. They rule in Hungary and Italy and will soon in the Czech Republic; even in historically social-democratic Finland and Sweden, conservative leaders rely on their support. They have a cheerleader in the Oval Office and another atop X.