On December 6, 2012 the Michigan House passed Right To Work legislation making Michigan the 24th state in the union to do so.
It didn't work out so well for the other 23 - in fact those who did so in the past are also the states with the lowest average wages, lowest employee benefits, the highest rates of welfare dependency, and the lowest economic growth.
We've embedded a .pdf below (download it here) that explains why Right To Work legislation is wrong for Michigan. It is comprehensive and provides sources for the data that it contains. Gordon Lafer is the author of the paper and it was written for the Economic Policy Institute.
A few other resources: