The adoption of the top two primary system in California is resulting in a rising number of general elections in which candidates from the same party compete. Incidentally, California is also home to a large and diverse Latino community. When party identification is no longer a reliable cue, do Latino voters turn to the race or ethnicity of a candidate in selecting whom to support? We examine co-partisan Republican general elections in California’s state assembly from 2012‒2016. Using surname-matched precinct-level voter data, we conduct ecological inference analysis to estimate support for candidates based on the ethnicity of voters. Taking the case of Latino voters, we find a strong level of support for Latino Republican candidates, suggesting that a candidate’s ethnicity may inform voters’ strategic decision making in partisan elections.