In 1977, Wallmann resigned his Bundestag mandate upon CDU winning a majority in Frankfurt's urban elections to become the Mayor of Frankfurt (at the time, the mayor was not directly elected). Frankfurt had been governed by SPD since the end of World War II, so the election marked a turning point with CDU winning an absolute majority in the city elections. This was largely regarded as backlash to the SPD's urban policies (Frankfurter Häuserkampf), primarily directed against land speculation in the city's west end and possible gentrification, also his predecessor Rudi Arndt (SPD) had been willing to dynamite the rubbish of the World War II ruins of the Alte Oper opera house to build a modern office building on the site instead. CDU was also helped by local SPD's party donations' scandal, and Frankfurt suffering from a high crime rate, being dubbed as Bankfurt and Krankfurt (krank meaning sick in German) in the media.
