In the last year and a half alone, 15 states have passed 28 laws preempting local labor standards: States passing preemption laws, by type of labor standard affected, January 2016–July 2017
Notes: Gray boxes represent laws passed in 2016. Blue boxes represent laws passed in 2017. PLA stands for project labor agreement.
In 2017, Missouri passed an amendment to a minimum wage preemption law that was originally passed in 2015; the 2015 law did not apply to an already-passed St. Louis minimum wage ordinance, but the 2017 amendment made the preemption retroactive to cover the St. Louis ordinance. In addition to the enacted laws listed here, an additional five bills were passed by three state legislatures (Maryland, New Mexico, and Virginia), but were vetoed by the respective state governors and were not enacted into law.
Source: EPI analysis of preemption laws in all 50 states