Click on figures to enlarge them.
Note that there are only four states that don't fit the pattern.
Virginia is a right-to-work state but it has a Democratic governor and a Republican legislature.
Iowa is a right-to-work state but Democrats only control one house of the state legislature.
Wisconsin isn't a right-to-work state but it has clear Republican control of the state.
Ohio isn't a right-to-work state but it has clear Republican control of the state.
Besides those four anomalies, all the other red states are right-to-work states and all the right-to-work states are red states. Still even these anomalies aren't that far off, Ohio almost became a right-to-work state and Wisconsin has changed the rules for public employee unions so that people can't be forced to join a union. And Virginia was close to having Republicans in control of the state. Iowa was also more red than blue.
Thus the two right-to-work states can hardly be classified as blue states and the two red states are hardly solid anti-right-to-work states.
The question is one of causation. Do already trending red states support workers making the their own decisions on whether they should join a union? Or do right-to-work laws make it so that unions can't raise a lot of money from people who don't want to be union members so that the unions can support Democrats? I don't know of anyone who has studied that question carefully.
Here is a list of states ranking them by the percent of workers in the state who are union members (Republican controlled and right-to-work states are in bold).
