Sure, the post-debate buzz is more about tone than substance — who looked more presidential, whether Hillary Clinton got “under Donald Trump’s skin.” But in between the barbs and interruptions, there was plenty of policy to chew over in Monday’s night’s presidential debate. Trump and Clinton tangled over trade, taxes, criminal justice and foreign policy, and while neither candidate — particularly Trump — provided many policy details, the back-and-forth was sufficiently substantive to expose stark differences between the candidates on a range of issues.