This paper considers how constitutional norms structure legislative deliberation. Its authors argue that the fact that legislators are ‘“responsible constitutional actors“ places them under an obligation … to deliberate about … constitutional rules when deciding whether to pass legislation‘. However, a complication is that some such rules are not judicially enforceable and may also be vague or unsettled. Considering Australian examples of legislative responses to organised crime and terrorism, the authors outline how an improved ‘broader deliberative process‘ that legislatively takes account of constitutional perspectives might look.