The party was one of the first in the world to articulate Marxist policies, even though the party was not as radical as others, such as the Communist Party of Germany (KPD). As the organized expression of a Democratic and Socialist political movement, it fought for policies for the German working class. It was due to the fact it was one of the only Socialist parties in Germany at the time, and that the working class made up the largest portion of the population, that it quickly became the biggest political party in the country.