Kulturkampf
In the age of nationalism, Protestant Germans, whether Conservative (like Otto von Bismarck) or Liberal, accused the Centre of Ultramontanism or having a greater loyalty towards the Pope than to their own nation. After the First Vatican Council, Bismarck launched the Kulturkampf or "cultural struggle" against the Catholic Church. But the Catholics fought back vigorously and with near-unanimity. The Centre party gained greater support from the Catholic population. Following Bismarck's 1878 turn from free trade to protectionism and from the National Liberal party to the Conservative parties, he also abandoned the unsuccessful Kulturkampf.
The Centre party remained a party of opposition to Bismarck, but after his resignation in 1890, it frequently supported the following administrations' policies in the Reichstag, particularly in the field of social security.
Read more about this topic: Centre Party (Germany)