Proportionality is the most successful case of constitutional migration and is often conceived to be a powerful signal of global constitutionalism, with the US standing as almost the sole exception to this phenomenon. Recently, Jamal Greene argued that proportionality is a better doctrinal candidate than the categorical approach to tackle the current challenges in US constitutional law. We argue, contrary to Greene, that proportionality may not be the best doctrinal candidate in the US taking into consideration the dramatic populist shift in the US. We wish to make a more general point about the use of proportionality in the new global age of populism. The rise of populism, and the increasing signs of democratic backsliding across the globe, require the employment of a more categorical approach, that better serves the purpose of red-lining and the enhancement of the democratic process.