The Leader of Social Democratic Party is elected by Party conferences, usually with around 600 delegates representing all the state and local party chapters. To stand as leader, a candidate needs to be nominated by 90 "Ortsvereine", local chapters. It is unusual for more than one person to be nominated as party leader, as the decision who becomes leader is usually made behind the scenes within the Presidium and Federal Executive. This has drawn hefty criticism, so much so that in the last leadership election in April 2018,
Simone Lange challenged
Andrea Nahles, the candidate nominated by the Federal Executive. This challenge, in German called "Kampfabstimmung" has only happened twice before; once in 1993 and once in 1995. ==Chairmen of the Social Democratic Party (1949–present)==