This Article constructs frameworks for analyzing federalism's undertheorized horizontal dimension. Discussions of … federalism generally focus on the hierarchical (or vertical) allocation of power between the national and state governments while … on state citizenship. This Article moves beyond the piecemeal approach by identifying facets of horizontal federalism …

to create a structure for a pandemic federalism that temporarily but responsively allows for a reconfiguration of public … addressing public health—has contributed to the nation’s unnecessarily excessive losses. Federalism has complicated governance … delivered conflicting messages to Americans about the importance of mask-wearing and vaccination. Federalism also enabled …