The incumbent campaigning for re-election in this weekend’s German election is one of his party’s heavyweights, an ambitious and confident bruiser with a talent for scorching populist rhetoric. His challenger is a woman, a diffident speaker in a party with few women in top leadership positions; her peers would mostly have preferred another man as their candidate. It seemed an easy win for the incumbent. Now, polls show the race is too close to call.

Déjà vu? Yes, but through the looking glass: in 2005, the woman who bested the Social Democrat chancellor, Gerhard Schröder, was a Christian Democrat, Angela Merkel. In this Sunday’s contest between Roland Koch, minister-president, and Andrea Ypsilanti in the western state of Hesse, the party affiliations are reversed and the Christian Democratic Union could suffer its first electoral setback in six years. This state election, one of four this year, has become not just a test of nerves but a national bell-wether: for Ms Merkel’s tenure as chancellor of a fractious grand coalition of the former rivals, the CDU and SPD, but possibly for the future of German party politics too.