We exploit a unique quasi-experiment to study the effects of judicial decisions on sensitive issues on political attitudes. In 2010, the Spanish Constitutional Court partially overruled the new Catalan Constitution–the Estatut–that granted further decentralization. Our identification strategy relies on the fact that this ruling occurred amid a public opinion survey. We find that the ruling increased support for independence by 5 percentage points. We interpret this result as evidence of judicial backlash on political attitudes: a judicial decision that limited further autonomy triggered a shift in attitudes towards even more autonomy. Moreover, the ruling decreased trust in the courts and satisfaction with democracy. This backlash of political attitudes extends to other spheres: Catalans increased their national identification with their region and the support for pro-decentralization parties. Finally, we show that the ruling increased polarization around the partisan and identity cleavages.