Why, despite increased female support, do social democratic parties (SDPs) in most Western European countries face electoral decline? To study this puzzle, we harness a well-documented regularity: diminishing support for SDPs by manual workers and their increased support for the far right. We contend that this trend is intensified in contexts where the economic positions of SDPs align with market-oriented policies or converge with those of the far right. Additionally, as men are disproportionately represented among manual workers, this shift contributes to the reversal of the gender gap in support for SDPs. Drawing on public opinion data from 18 countries spanning half a century, along with labor and party economic position data, our findings substantiate this argument.