The German Greens have been flying high in the polls in recent months. Now standing at 18 percent, support for the party has soared to its highest point since the Fukushima nuclear disaster. Last Sunday the Greens more than doubled their vote share in the Bavarian state election, taking 17.5 percent. The party also looks set to come in second in the state of Hesse next weekend.

But the performance spike comes as somewhat of a surprise: the Greens netted a mediocre 8.5 percent in last year’s federal elections, almost unchanged from 2013. The party hasn’t veered much from its centrist path since its failed attempt to form a federal coalition with Chancellor Angela Merkel’s Christian Democratic alliance (CDU/CSU) and the pro-business Free Democrats (FDP) following the 2017 general election — moves that disgruntled the Greens’ more radical youth wing. But if the party hasn’t changed, what else has?

The answer lies in the performance of Germany’s ruling parties, today joined in a grand coalition. Following multiple cabinet showdowns this summer, each of which brought the gears of government to a halt, discontented voters from all the ruling parties — the CDU/CSU and the social-democratic SPD — seem to be drifting toward the Greens. Just over two-fifths of the Green’s new supporters have migrated from the SPD and a quarter have wandered over from the CDU/CSU, according to a poll published in Die Welt newspaper.