On the rocky road towards Germany’s post-Merkel future, one thing used to seem certain: the shoes of the first female, Protestant East German scientist at the top of German politics would be filled by a male Catholic Rhinelander with a law degree.

That description still fits all the three official candidates who at a party congress in early December will pitch to lead Angela Merkel’s Christian Democratic Union, the indispensable behemoth of postwar politics in Europe’s largest economy.

But the pandemic has realigned the stars for some of its top politicians to the extent that CDU insiders worry the leadership race’s most likely outcome no longer looks ideal, and the ideal outcome for the greater good of the party looks unlikely.

The impressive lead the conservatives have built up through their handling of the Covid-19 threat, they fear, could melt away as a squabbling party emerges from the shadow of the chancellor that has unified them for the last 15 years.

Merkel, who will not be running for a fourth term at federal elections in 2021, has already had to tear up her succession plan once: her designated continuity candidate, Annegret Kramp-Karrenbauer, who took charge of the CDU in December 2018, announced her resignation a year later, her authority diminished by a series of internal power struggles.

Before the onset of Covid-19, a new chair was due to be crowned at a party congress in late April. Armin Laschet, the moderate state premier of North-Rhine-Westphalia, looked like the top contender after winning over the ambitious young health minister, Jens Spahn, as his number two.

Laschet, a loyal defender of Merkel’s refugee policy in 2015, also has the advantage that his home turf is Germany’s most populous state, providing almost 30% of the 1,001 delegates who get to cast their vote on the future leadership. But the 59-year-old with Wallonian roots has floundered during the pandemic, in which he emerged as one of the most prominent voices of relaxing social distancing restrictions – only to then have to coordinate Germany’s first “second lockdown” following a Covid-19 outbreak at an abattoir in Gütersloh. In the eyes of many voters, “pushy Laschet” looked more concerned with local business lobbyists than the welfare of the country as a whole.

“It’s hard to imagine Laschet staring down Putin, Xi or Trump,” said one previously sympathetic CDU delegate.

As Laschet’s popularity ratings nosedived, another conservative politician rose to unseen heights: polls showed the Bavarian premier Markus Söder, who had introduced a lockdown in Germany’s southernmost state before it came into place in the rest of the country, to be the most popular politician in the country.

“In a world that is increasingly marked by insecurities – through migration movements, climate change or global pandemics – we are seeing a high preparedness to trade some basic rights in exchange for stability,” says Wolfgang Merkel (no relation), a political scientist at Berlin’s Humboldt University.

A recent study authored by Merkel shows populist attitudes in Germany to be in steep decline after rising during the refugee crisis – a trend, he says, which was accelerated by strong statesmanship by established parties at the height of the pandemic.

“For governments, there is a new premium on leaders who can demonstrate strength and act decisively, albeit without the populist rhetoric. For the CDU, that means polls will be crucial for choosing its chancellor candidate, and for now they point towards Söder rather than Laschet.”

As the leader of the CDU’s sister party, the Bavarian Christian Social Union (CSU), Söder won’t be in the running when delegates gather for a socially distanced one-day congress in Stuttgart this winter, most likely on 4 December.

But he could become the two parties’ candidate for the chancellory – an option that has been tried before, with an unhappy ending for the conservatives. Both in 1980 and 2002 the CDU/CSU lost an election as a result, and many still believe that Bavarian politicians with their broad accents and overtly Catholic brand of conservatism simply cannot win enough votes north of the river Main.

Söder’s growing band of vocal admirers point out that their man is in fact from Franconia, and a Protestant at that. “He’s the least Bavarian leader the CSU has ever had,” says one fan.

For the 6ft 4in southerner to run, however, he would need the support of the head of the CDU in Berlin: something that Laschet would be as unlikely to offer as Friedrich Merz, the veteran hardliner and Merkel critic who is seen as the number two in the three-horse race for the leadership.

Some Christian Democrat MPs envision a “dream ticket” of Söder and Spahn, whose star has also shone brightly during the pandemic. But for the openly gay 40-year-old to run for the leadership would require reneging on his deal with Laschet. “In politics everyone loves betrayal, but no one loves a traitor,” said an official at the CDU headquarters when asked about such an option.

There’s an outside chance that the fiendishly complicated reshuffle at the top of Germany’s biggest party could benefit the outside candidate: Norbert Röttgen, the third Catholic lawyer from Rhineland-Westphalia on the ballot.

After leading the CDU to a crushing defeat in his home state in 2012 and losing his job in Merkel’s second cabinet as a result, the former environment minister has slowly crept back into the limelight through his role as chair of the Bundestag’s foreign affairs committee.

As the Alexei Navalny/novichok affair has forced Germany to reconsider its approach to Russia, Röttgen’s outspoken views have impressed conservatives who are frustrated with Laschet and Söder’s soft-pedalling. But the suave, sometimes over-confident 55-year-old’s biggest asset could be his openness to ceding the chancellor candidacy to Söder. If Röttgen made it to the second round, he might end up with the votes of the embittered supporters of one of the two frontrunners almost by accident.

Merkel’s line of succession, which has been planned, postponed and redrawn continuously over the last decade, could in the end be a matter of chance.