In our 2018 Editorial, we highlighted a paradox within global constitutionalism. Even while then-President Trump was publicly undermining foundational norms of constitutionalism through his ‘breaching experiment’, these attacks were simultaneously fortifying such constitutional norms. Conspicuous attacks reinforce the importance of shared civic norms that underpin constitutional democracy. Citizens and leaders responded to Trump’s attacks by stiffening their resolve to protect and entrench the values of democracy. Where the public assaults upon such norms are extraordinarily blatant (as Trump’s assaults were), it may lead to especially robust counter-mobilisation. While the Trump presidency illustrates the ease with which a public office holder can violate liberal democratic norms, the backlash against Trumpism also demonstrates how robust the commitment is to norms of global constitutionalism.