Why are rich citizens not taxed more heavily – despite growing inequality (aversion)? Several explanations for this puzzle exist at different analytical levels: voters’ decision-making, party-interest-group linkages or international competition. Crucially, all of them ultimately work through the minds and actions of politicians and, hence, through economic ideas. Taking Germany as a case, we therefore ask which obstacles left-wing politicians perceive in taxing the rich. In 25 semi-structured interviews with actors from parties and interest groups, we tease out subjective accounts for the failure to tax the rich. Overall, tax increases are perceived as unpromising political projects. Organized business interests are described as a major barrier, but in a way that goes beyond most existing accounts: besides classical lobbying, business interests are seen to influence electoral politics through long-term communication strategies that shape public opinion on tax issues. Moreover, the interviews point to a previously unrecognized barrier: organizational dynamics within left-wing parties around the production of tax competence. Left-wing politicians are often overwhelmed by tax issues which results in consequential disadvantages when confronted with resourceful anti-tax actors. They describe how party-internal discourses shape these competence patterns by influencing motivations, feasibility perceptions, and electoral strategies.