Friedrich Merz, the leader of Germany’s Christian Democratic Union (CDU), dropped the bomb last weekend. In a TV interview, Merz opened the door for collaboration with Alternative für Deutschland (AfD), the nationalist-populist party that is home to Germany’s cabal of crackpots and right-wing extremists. He didn’t say what form such co-operation would take, but talked about finding ways to run local councils when the AfD won democratic elections – which happened a few weeks ago when Hannes Loth won a mayoral race in a small town in Saxony-Anhalt.