Objective We examine how Latino constituencies—their percentage of the population and their percentage of voters—influence the propensity of states to pass restrictive immigration policy, testing two competing theories. Method Using state‐level data from 2009 through 2012, we examine the influence of Latino constituency size and Latino electoral strength on the number of restrictive immigration laws enacted by U.S. state legislatures. Results We find that states with larger Latino populations pass more restrictive laws, but greater Latino electoral strength leads states to pass fewer restrictive policies. This relationship is interactive such that increases in Latino turnout act to mitigate the positive effect of Latino population size on restrictive policies. Finally, we show that the positive effect of Latino mobilization is indirect, meditated by their electoral influence on the partisan and ethnic composition of state legislatures. Conclusions Our findings emphasize the importance of voting for minority substantive representation.