A decade of failure and frustration profoundly shaped the theory and strategy of the Düsseldorf Social Democrats. Isolation and defeat, intensified by the turn-of-the-century economic crisis, confirmed their skepticism about parliamentarism and reformism and their opposition to proposed alterations in the party's program and practice, which emanated from the right. Their experiences made them receptive to a conception of revolution that emphasized economic development and not working-class activism as the crucial component of a socialist transformation. Their advocacy of orthodox Marxism, isolation, and tactical passivity both reflected and reinforced the weakness of the local movement and the stalemate of national politics.

Their experiences and the lessons they drew from them conditioned their negative and dismissive response to the revisionist controversy that shook the national movement at the turn of the century. They condemned Bernstein's proposals for revising Marx's economic analysis and reorienting the SPD's political strategy, and lashed out bitterly at bourgeois intellectuals who stirred up futile controversies. But they rejected revisionism without articulating an activist and radical alternative. They thus found themselves closer to the party's mainstream than they had previously been – or ever were to be again. Like their comrades elsewhere, they found that deterministic, orthodox Marxism offered hope in the face of failure and legitimated isolation and passivity. It did not, however, provide a way out of the dilemmas and disappointments of the 1890s.

The same failures that unified the party ideologically divided it organizationally. In response to renewed economic recession, continued Center Party success, and government harassment, the Social Democrats fought bitterly over questions of party structure, the press, and leadership.