AfD is polling 17-19% nationwide, around a record high for the party that now vies with Chancellor Olaf Scholz's Social Democrats for second place in some surveys, up from fifth in the 2021 election when it secured 10.3% of the vote.
It was last at such highs in 2018 after Europe's migrant crisis. This time, the nationalist, anti-immigrant party has also benefited from infighting in Scholz's three-way coalition.
Far-right parties have gained ground across Europe. In France, the far-right has become a stronger rival at the ballot box, while in Italy and Sweden, they are now are in government.
But the rise of the AfD, which lambasts the German government for high immigration levels, surging inflation and a costly green transition, touches a particularly sensitive nerve in Germany because of the country's Nazi past.
Germany's domestic spy agency has branded the AfD's youth wing "extremist", saying it propagated "a racial concept of society". The spy agency's head has also accused the AfD, which opposes sanctions on Russia, of helping spread Russian propaganda about the Ukraine war.
Germany's main parties have ruled out cooperating with the AfD to keep it out of government, but the AfD's critics worry that it is dragging mainstream politics further right.
"We are seeing the rhetoric on topics like migration get shriller," said Stefan Marschall, political scientist at the University of Duesseldorf.
Migration is moving up Germany's political agenda. Michael Kretschmer, the premier of the east German state of Saxony and who is from the right of centre Christian Democratic Union (CDU), said last week that the number of migrants was "too big", calling for limits on refugees allowed in and cuts to benefits.
THE COST OF TRANSITION
The CDU's national leader, Friederich Merz, has however dismissed any comparisons with the AfD, saying in comments on Sunday that his party's language was "nothing like" the AfD's.
Meanwhile, Interior Minister Nancy Faeser has partly blamed the AfD for stoking anti-immigrant attitudes that have fuelled a rise in attacks on refugees. The AfD denies this.
The AfD, which disputes that human activity is a cause of climate change, has also tapped into concerns among some voters about the cost of the transition away from fossil fuels.
AfD leader Tino Chrupalla said more voters appreciated that the policies of the Greens, Scholz's junior coalition partner which wants a swifter shift away from hydrocarbons, brought "economic war, inflation and de-industrialisation."
"We are the only party that would not form a coalition with these dangerous Greens," he said.
In Thueringen, Saxony and Brandenburg, the east German states that are holding state elections in 2024, the AfD is on track to top voting for the first time, with surveys showing its support at 23%-28%.
Analysts say voters in the east, where party loyalties are less well-established, have been more receptive to the AfD in part because they blame mainstream parties that have rotated through various governments over the years for lower incomes that persist in the east, three decades after reunification.
Even if the AfD's is kept out of power, its rise has sucked votes from other parties, forcing them into more unwieldy coalitions at state and national levels, particularly in the east where the AfD is strongest.
WAVE OF DISCONTENT
Marc Debus, a political scientist at Mannheim University, said it could bolster calls among some voters for conservatives in particular to work more closely with the AfD, even if not in a formal coalition, rather than aligning with the left.
Some AfD initiatives have won backing from mainstream voters on the more local level. In December, members of the CDU in the small town of Bautzen in Saxony voted in favour of an AfD proposal to cut some benefits, such as language courses for migrants whose asylum applications had been rejected.
"This dogmatic way in Berlin of excluding the AfD, saying they are all Nazis, is wrong," said Matthias Grahl, head of the CDU in the Bautzen district council.
Others say the AfD is riding a wave of discontent because of a confluence of crises that will not last. Inflation has already dipped from its peak and sky-high energy prices over the winter, fuelled by the Ukraine war, have eased.
Wolfgang Buechner, a Scholz government spokesman, said he was confident the coalition could whittle away at AfD support.
"The chancellor is optimistic that if we do good work and solve the problems of this country ... then we will not need to worry much longer about this topic," he said.
(Reporting by Sarah Marsh; Additional reporting by Andreas Rinke and Madeline Chambers; Editing by Edmund Blair)
