Germany’s Die Linke was once the shining light of the European left. Created in 2007 as a merger between the postcommunist Party of Democratic Socialism (PDS) and a pro-labor breakaway from the Social Democratic Party (SPD), in its first decade Die Linke became a major force in national politics. In the East, it represented left-behind young people and pensioners and drew attention to the inequalities bequeathed by reunification. In the cities, it was the obvious political home for left-wing students, radical trade unionists, and activists of all kinds. At its height, it routinely scored around 10 percent nationally and nearly 30 percent in many former eastern states, even entering government there.
Yet today…