Preemption is typically a bad thing (big business and their lawyers typically disagree with me on this). In a nutshell, preemption is the ability to one set of laws to override another set. Typically, the context is that the federal law says ‘A,’ a state’s laws say ‘B,’ and so ‘A’ wins. Of course, the way our country was set up, we encouraged states to experiment with their own laws.
Applied to the medical arena, many medical device manufacturers believe they should be immune from lawsuits for defective devices (devices may be defective for any number of reasons—they may have been designed incorrectly, the manufacturing process may have had errors, or they may come with improper warnings). Sadly, the Supreme Court agreed that the law allowed that conclusion in Riegel v. Medtronic, Inc.