Konrad Adenauer, West Germany’s first post-second world war chancellor, won the most convincing election victory of his political career in 1957 with the campaign slogan “No Experiments”. This reassuringly cautious message echoed around Germany on Saturday as delegates chose Armin Laschet, the state premier of North Rhine-Westphalia, to be the new leader of the governing Christian Democratic Union party.

Mr Laschet, 59, was Chancellor Angela Merkel’s preferred candidate. He represents the brand of soothing, prudent centrism that enabled her to neutralise her political opponents and win four successive elections between 2005 and 2017. However, his victory leaves important questions unanswered about how the CDU will fight September’s Bundestag elections and, in a larger sense, about the party’s post-Merkel ideological profile.

The first point is that Mr Laschet may not even be the candidate for chancellor of the centre-right alliance made up of the CDU and the Christian Social Union, its Bavarian sister party. This honour may go to Markus Söder, the CSU leader and Bavarian premier, or even to Jens Spahn, Germany’s health minister, who supported Mr Laschet for the CDU leadership but is thought to have ambitions of his own for the chancellorship.

Both Mr Söder and Mr Spahn have performed well under pressure as the Covid-19 pandemic gripped Germany, whereas Mr Laschet has stumbled from time to time and seen his popularity ratings fall. Many politicians and activists in the CDU’s conservative wing, and in the CSU, do not think Mr Laschet is the best man to lead the alliance in the Bundestag campaign.

The second point concerns the CDU’s political direction after Ms Merkel’s departure. The party enjoys a commanding lead in opinion polls at present, but this disguises the fact that it has found it increasingly difficult in the Merkel era to hold on to its electorate.

In 2017, the CDU-CSU bloc took just under 33 per cent of the vote, its worst result since the first postwar West German elections of 1949. In the European Parliament elections of 2019, the CDU-CSU vote fell to 28.9 per cent.

The CDU has stayed in office partly because the centre-left Social Democrats are in even more serious trouble and have clung to their historic rival in “grand coalitions”, which have formed three of Germany’s last four governments. Germany’s mainstream parties have also been wary about sharing power at national level with two parties of the radical right and left — Alternative for Germany and Die Linke.

If Mr Laschet is the centre-right’s candidate for chancellor, it might make one potential combination after September’s elections — the CDU and Greens — more elusive. Although Germany intends to phase out coal production by 2038, Mr Laschet is a stout defender of North Rhine-Westphalia’s lignite industry. He angered environmentalists last year when he supported the opening of a new coal-fired power plant, Datteln 4, in his home state.

Another awkward problem for the CDU is that it is internally divided over how to deal with the rightwing populist AfD, especially in eastern Germany. In the 2017 election, more than 1m former CDU and CSU voters switched to AfD.

Some CDU politicians in the east want to form local coalitions with AfD despite the opposition of the CDU’s national leadership. Ms Merkel’s first successor as CDU leader Annegret Kramp-Karrenbauer was brought down last year by the local CDU’s dabbling in such a scheme in the eastern state of Thuringia.

The CDU delegates who elected Mr Laschet are calculating that Merkel-style centrism remains a political project attractive enough to deliver another election victory in September. Yet without the towering figure of the chancellor herself at the helm, the party faces hard choices about its future.