SPD party leader and German Vice Chancellor, Economy and Energy Minister and Sigmar Gabriel (L) and Berlin's mayor Michael Mueller, top candidate of the social democratic SPD party shake hands during the electoral evening in Berlin after a regional election on September 18, 2016 in Berlin. Some 2.5 million eligible voters in Berlin will choose both a new city-state parliament and 12 local district assemblies. / AFP PHOTO / Odd ANDERSENODD ANDERSEN/AFP/Getty Images