The analysis allows for a more comprehensive test of the new judicial federalism thesis regarding State court reliance on State constitutions. One-third of the challenges to State law were brought on Federal grounds and 44 percent on both State and Federal grounds. These cases include challenges based on both analogous and nonanalogous State and Federal provisions. Twenty-two percent of the challenges before State supreme courts were brought on State grounds only. The invalidation rate for challenges based only on State grounds was more than twice that for challenges based solely on Federal grounds. State courts were more activist when the challenges were made on State constitutional grounds. On balance, the study findings offered limited support for the new judicial federalism. 15 footnotes, 2 tables, and 14 references