How did you get absolutely no support for the SPD?
Viewing post in Social Democracy: An Alternate History comments
At the start of the game, take the shuffle leadership card, fire everyone, hire everyone from the left faction, fire everyone from the left faction, hire everyone back from the left faction, repeat until very high for dissent for the left faction, repeat for each faction, so everyone—centrist, leftist, labour, and reformist—resigns, causing a collapse in the polls as the SAPD gets very large. Then, pick only bad cards, such as enforcing party discipline, increasing fundraising, and decreasing Reichsbanner funding. After each election, always pick no governing majority. Repeat until after the great depression and Hitler will be the chancellor. For the Young Plan event, do not campaign for either side. Remember not to pick the right-wing coalition after every election. Now, only 1% of Catholics and 0% of everyone else like the SPD. 1 seat SPD is now formed.