As a co-founder of Arbeiterpolitik and a member of the Bremer Linksradikale, the Social Democrats' radical left-wing in Bremen, he was briefly imprisoned in June 1916 for distributing illegal pamphlets.
[citation needed] Brodmerkel was a delegate of the Bremen left-wing radicals during the April 6, 1917 founding conference of the Independent Social Democratic Party of Germany (USPD), in Gotha.
After the election of a hundred and eighty deputies the Action Committee was completed, and a workers' and soldiers' council was formed.
After the failure of the revolution, Brodmerkel was elected a deputy of the Bürgerschaft (Parliament) of Bremen in 1923, as a representative of the Communist Party.
In early 1925, Brodmerkel was expelled from the Communist Party together with Adolf Ehlers and Wilhelm Deisen on charges of being right-wing, but was readmitted by the end of the year.