A savvy electoral campaign against two lacklustre opponents has put the SPD leader ahead in the polls to succeed Angela Merkel
Of all the political posters and billboards that line the streets of German towns and cities this late summer, the ones most likely to stop commuters in their tracks are those bathed in traffic-light red.
Using a stark colour scheme usually exclusive to the Marxist-Leninist parties on the fringe of the German left, the posters are surprising in more ways than one: in the centre of the picture sits a bald, suited man who looks less like a leftwing rabble-rouser promising you radical change than a middle manager at a regional building society scrutinising your loan application.