PERHAPS it was the impeccably proletarian setting: a vast former coal mine in the industrial Ruhr. Or perhaps it was the 1,500-strong crowd chanting “Martin! Martin! Martin!” Or perhaps it was the sound system blaring the upbeat 1990 hit “I’ve got the power”. But for some reason Martin Schulz, the Social Democratic (SPD) candidate for Germany’s chancellorship, got carried away and said something rash at his early-April rally in Essen. If the SPD won the state election here in North-Rhine Westphalia on May 14th, he proclaimed, it would go on to become “the strongest force in Germany” and eject Angela Merkel at the general election in September.

The Essen rally coincided with the so-called Schulz-Effekt, the surge in support for the SPD following Mr Schulz’s coronation as party leader in January, which saw it draw almost level with Mrs Merkel’s Christian Democrats (CDU) for the first time in five years. Its poll numbers in North-Rhine Westphalia, Germany’s industrial heartland and most populous state, and Schleswig-Holstein, its northernmost state which votes on May 7th, had also jumped (see chart).

The SPD has run both for over 20 of the past 30 years. Its premiers are popular and seem relatable: Hannelore Kraft in North-Rhine Westphalia is known as “Landesmutter”, or mother of the state; Thorsten Albig in Schleswig-Holstein could pass for a schoolteacher. In both Düsseldorf and Kiel the party governs with the Greens, its favourite coalition partners. Back in early April it seemed elections in both states would give the SPD a morale-boosting shove into the national campaign.

But since then the Schulz-Effekt has cooled. The party has fallen back below 30% nationally. The most likely outcome in the North-Rhine Westphalia is an SPD-CDU grand coalition, led by whichever emerges as the largest. In Schleswig-Holstein the CDU is now ahead and might oust the SPD in favour of a coalition with the Greens and the liberal FDP.

Germany’s 16 state governments run everything from schools and police forces to motorways and health systems; their leaders are big figures in their own right. So the suggestion that state elections are mere tests for federal politics “implies that voters do not know what they are voting on,” argues Manfred Güllner, founder of the Forsa polling agency. He notes that the CDU’s grim defeat at the last election in North-Rhine Westphalia, in 2012, came a year before voters in the state resoundingly backed Mrs Merkel in a federal election.

These voters also have reasons to give the SPD a kick. Even party insiders admit that North-Rhine Westphalia is a mess. It has the worst traffic jams and the highest level of child poverty in Germany, and the highest unemployment rate outside the former-communist east. It was here that hundreds of women were sexually assaulted in Cologne on New Year’s Eve in 2015. It was here that Anis Amri, the Tunisian immigrant who drove a truck through a Berlin Christmas market in December, slipped between gaps in the asylum system. Bild-Zeitung, Germany’s main tabloid, branded it “The Greece of Germany”.

Schleswig-Holstein is less troubled. One study claims it is the happiest part of the country. Mr Albig’s steady government is a relief in a state previously plagued by drama (one of his predecessors was found dead in a bathtub in Geneva). But Daniel Günther, his CDU rival, has plenty of material to work with: slow autobahn improvements, unreliable rural internet, and above-average unemployment.

Picking apart state issues and national personalities is tricky. Mr Schulz has campaigned extensively in both states. He lives in North-Rhine Westphalia, used to be mayor of a small town there and is a proud Rhinelander. Senior Christian Democrats and Social Democrats from across the country have converged on the two states. Mrs Merkel alone will have made eight visits to North-Rhine Westphalia by the election. “If we don’t hold both it’s really bad news,” admits one senior SPD figure.

The results of the two elections will affect the morale of the two parties. A few weeks ago the Schulz-Effekt was energising the SPD and roiling the CDU; some of Mrs Merkel’s MPs were even quietly opining that she was past it. All that has changed as the polls have turned, and will change even more if North-Rhine Westphalia and Schleswig-Holstein confirm the trend. There is almost half a year to go until Germany’s election. But for now, Mrs Merkel has the momentum.