Perhaps hundreds of survey experiments have shown that political party cues influence people’s policy opinions. However, we know little about the persistence of this influence: is it a transient priming effect, dissipating moments after the survey is over; or does influence persist for longer, indicating learning? We report the results of a panel survey experiment in which U.S. adults were randomly exposed to party cues on five contemporary U.S. policy issues in an initial survey, and gave their opinions. A follow-up survey three days later polled their opinions again. We find that the influence of the party cues persists at ~50% its original magnitude at follow-up. Notably, our design rules out that people simply remembered how they previously answered. Our findings have implications for understanding the scope and mechanism of party cue influence as it occurs in the real world, and provide a benchmark for future research on this topic.