He replaced Hüseyin Kenan Aydın as the state spokesperson for the Labour and Social Justice – The Electoral Alternative in June 2005, and in November of that year, he was re-elected as spokesperson, together with his colleague Katherina Schwabedissen.
During the inaugural convention of the Left in North Rhine-Westphalia in Gladbeck on 20 October 2007, Zimmermann became the state spokesperson with 256 of 287 votes cast. He shared this office with Ulrike Detjen until 18 October 2008. During the state party convention on 18 October 2008, which was held in Essen, he was again elected to be spokesperson with 156 of 226 votes cast. Following the departure of Ulrike Detjen, he served in this position with Katharina Schwabedissen until July 2010.
In the 2010 state election, Wolfgang Zimmermann won a seat in the Landtag of North Rhine-Westphalia as the second person on the state party lists. In the inaugural meeting of the parliamentary group, he was elected (together with Bärbel Beuermann) to be the group's spokesperson.[1] In the 2012 state election, the party again selected him to be listed second on the party lists. During a medical examination in the course of his campaign, he was discovered to have lung cancer, but despite this, he did not end his bid for election. When the Left failed to garner enough votes to surpass the 5% threshold required to remain in parliament, Zimmerman lost his seat.
Zimmermann occasionally writes articles for the Socialist Newspaper (Sozialistische Zeitung) and is associated with the "Anti-Capitalist Left", an anti-capitalist, anti-militarist caucus within the Left Party.
