Victor Adler was the member of the group to make the most visible mark in the realm of politics, most notably presiding over the Social Democrats in attainment of universal manhood suffrage in 1907 and the revolution that brought about the Austrian Republic in 1918. And his influence extended beyond his life in ways he could not have imagined: It was from Adler's Social Democrats that Hitler claimed he learned the most about mass organization and psychology.
Adler was a central member of the circle from the beginning. Adler and Pernerstorfer were close friends and remained in significant contact throughout their lives. The earliest meetings of Circle members occurred in the home of Adler's father, a prosperous Jewish merchant.
Adler shared his early enthusiasm for Schopenhauer with other members of the group. He was also one of the first members of the group to join the Academic Wagner Society (in 1876, one year after the Society's founding) and to make a pilgrimage to Bayreuth. He was among the members of the Circle who signed a letter to Nietzsche indicating their goal to promote and follow the vision described in his Birth of Tragedy.
He, along with Pernerstorfer and Friedjung, were central in the development of the Linz Program and the deutschnational movement. At the same time, his work as a doctor in meeting the medical needs of the poor informed his vision of social reform. While involved in the deutschnational movement, he began making contact with socialist thinkers and leaders, many engaged in a highly nationalistic brand of Marxism. In 1886 he founded the socialist weekly Gleichheit (Equality) and in 1889 the Arbeiterzeitung (Worker Times). Over time, his interest in nationalist politics diminished in favor of activist socialism. However, Adler's interest in art and culture (and in Wagnerian theories of mass will) were reflected in the cultural emphasis of socialism in Austria and in the spiritual and cultural symbolism of Adler's political tactics and oratory.