Cool! If the OP or anyone wants to try this across all US caselaw (as opposed to just Supreme Court) we recently released a data set of citation data at the Cas

Cool! If the OP or anyone wants to try this across all US caselaw (as opposed to just Supreme Court) we recently released a data set of citation data at the Caselaw Access Project: https://case.law/download/citation_graph/ https://case.law/download/citation_graph/ I used that data to build a visualization of how often states cite each other, for example: https://case.law/exhibits/cite-grid https://case.law/exhibits/cite-grid