Seehofer's CSU faces historic flop at Bavarian polls

Recent polls put the CSU at 33-35 percent, and the AfD, which is running for the first time for the Bavaria parliament, is expected to get 11-14 percent of the votes. In 2013, the CSU won a commanding 48 percent of votes in the regional and last year received 39 percent of votes at the federal elections.

Following the knee-jerk reaction of other rightwing parties facing hard-right challengers, CSU leaders have started to talk tough on migration, and the powerful CSU interior minister in Berlin, Horst Seehofer earlier in the summer threatened tobring down the government over details of Merkel's migration policy.

The CSU's aggressive rhetoric on migration and its combative politics in Berlin has put off many of its moderate supporters who have fled to the Green party, which is expected to finish second with 18 percent, ahead of the social democrats.

After the party's poor showing at the federal elections last year, CSU leader Seehofer, 69, stepped aside as prime minister in Bavaria in March to make way for Markus Soder, 51 - who has entered office with controversy after his cabinet ordered that Christian crosses be on display in public buildings.

Bavaria, with a population with 13 million, is one of Germany's most prosperous regions with unemployment below three percent, and home to many global brands, such as BMW, Audi and Adidas.

Yet migration, after Bavaria saw over a million people crossing from neighbouring Austria in 2015, still dominates politics.

Seehofer and Soder have also been locked in a bitter rivalry, and the party's weak performance at the polls will be decisive for the future of Seehofer as party chairman and federal interior minister.

"The bottom line of these elections is the future of Seehofer, who has been undermining the coalition in Berlin," Judy Dempsey, a senior fellow at Carnegie Europe told EUobserver, pointing out that the election's outcome will be crucial for the federal coalition.

"If the polls are right, and CSU loses big, the blame-game will begin, to which Seehofer could be a victim - some of it his own making. Seehofer's move to the far-right has shaken the coalition in Berlin, and shaken the confidence of the public," she said.

Dempsey added that Seehofer's anti-EU rhetoric, talk of closing down borders, and relentless criticism of Merkel has alienated voters, some of whom thought his handling of migrants fleeing war was not very 'Christian' (the CSU has long been viewed as 'the respectable right' in German politics.)

The party's long-time chairman between 1961 and 1988, Franz-Josef Strauss, famously remarked that there should be no space for a democratically-legitimate party to the right of the CSU.

"Moving to the far right, CSU voters aren't comfortable with this," Dempsey said.

A key question is how the CSU's weak performance will impact on Merkel's government, and if Seehofer will be forced out.

Dempsey said a weakened Seehofer could ease the pressure on Merkel - but the chancellor needs to act fast to seize the momentum and strengthen the coalition before her party's congress in December.

"She has to show that she has new authority," Dempsey added.

But Merkel does not have a lot of time, as her influence in her own party also faltered when last month the CDU's parliamentary group narrowly ousted Volker Kauder, their leader of 13 years, and a close ally of the chancellor.

EU ramifications

The CSU's poor showing will also not help Manfred Weber, who hails from the Bavarian party and recently announced his bid for the European Commission's top job as a possible lead candidate - or Spitzenkandidat - of the European People's Party.

Another side-effect of the Bavarian elections could be the strengthening of the Greens, which could potentially become a coalition partner in Bavaria, increasing their influence at federal level.