The Mississippi state House passed several measures explicitly aimed at limiting the actions that unions can take. The measures that passed were aimed to prohibit mass picketing that blocks entrances, prohibit state or municipal governments from requiring that contractors use union labor, and to prevent actions which would cause businesses to remain neutral during organizing drives. Democrat House members attempted to amend some of the laws to make them harder to implement, but were vastly outvoted. The Mississippi AFL-CIO president said that some of the laws violate federal protections, but that all are meant as intimidation tactics against employee collective action, not just against unions.
See "House Oks bills restricting union activity", Geoff Pender, Clarion-Ledger, March 5, 2014