Coal-fired power generation is the single most important source of carbon dioxide emissions in many countries, including Germany. A government commission recently proposed to phase out coal by 2038, which implies that the country will miss its 2020 climate target. Based on a representative sample of German voters assessing 31,744 hypothetical policy scenarios in a choice experiment, we show that voters prefer an earlier phase-out by 2025. They would uphold their support for greater climate ambition up to an additional cost to society of €8.50 billion. Voters in Rhineland and Lusatia, the country's main coal regions, support an earlier phase-out, too, although to a lesser extent. By demonstrating that political decision-makers are more reluctant to overcoming energy path dependence than voters, our analysis calls for further research explaining the influence of particular stakeholders in slowing energy transitions.