What leads states to adopt more restrictive labour policies? The conventional wisdom is that unified Republican states, with help from conservative political networks, are more likely to adopt restrictions on labour unions. We argue that party control of government matters but is constrained by voter preferences and the power of organised labour. We create new estimates of state-level public support for unions by income thirds using dynamic multilevel regression and poststratification. Using this measure, we predict the adoption of restrictive labour policies, such as right-to-work and minimum wage preemption laws. We find that Republican governments are less likely to adopt restrictive policies when unions are strong and when union support among middle- and low-income earners is high. Interestingly, these results run contrary to much of the literature on the unequal representation of the wealthy in public policy.