Citizen activists play a role in translating public concern about the climate crisis to policymakers and elevating it on the political agenda. We consider the dynamic between citizen activists and the decision-makers they seek to influence and we review psychological research relevant to advocating for climate legislation. We conducted a study with citizen activists who lobby the US Congress for a carbon pricing policy to address climate change. The study assessed how activists think about four social psychological approaches: affirmation, social norms, legacy and immediacy. The findings provide a window into activists’ intuitions about which strategies to use, whom to use them with and their perceived effectiveness. A strategy of establishing shared values and common ground (affirmation) was used most frequently overall. A strategy emphasizing the long-term costs and benefits of addressing climate change (legacy) was employed less frequently than affirmation and seen as less effective by activists but it was the only strategy that was associated with perceived increases in Congressional Representatives’ support of the policy. Citizen activists and their interactions with elected officials provide an opportunity for social-behavioral scientists to understand and potentially overcome barriers to enacting climate policy.