Geographic distribution thumb|left|2021 federal election SPD results Much of the SPD's current-day support comes from large cities, especially northern and western Germany and Berlin. As of 2019, 10 of the country's 15 biggest cities are led by SPD mayors. The metropolitan Ruhr Area, where coal mining and steel production were once the main industries, have provided a significant base for the SPD in the 20th century. In the city of Bremen, the SPD has continuously governed since 1949.
GeograpHic DiStrIbutIon thumB|lefT|2021 federAL ElEctioN spD rESultS much OF thE sPd's CUrrEnT-Day SUpPort coMes fRoM lARge citIeS, EspeciaLly nOrtHern and WEsTErn GerMany and berlIN. as of 2019 10 of The couNtry's 15 biggest citiEs are leD by SPd mayOrs thE mEtropolitan ruhr ARea, wherE CoAL miniNg aNd SteEl PrOducTIon wEre OnCe tHE mAin iNdUstRies havE ProvideD A SigNificanT basE fOR tHE sPD In tHe 20tH centuRY. iN the ciTy of breMeN, the spd hAs cOntinUoUSly GOverned sincE 1949.