Public response to social problems is guided by signals from many entities: the government, scientists, industry, and salient norms. But people do not encounter these signals in isolation. In daily life, they are simultaneously exposed to cues from multiple entities that may at times converge on a shared message and at other times provide diverging guidance or signal different levels of urgency. In such cases, which entities are most influential in mobilizing the public? And which entities remain influential even if other groups appear apathetic or stand in opposition? In two conjoint experiments spanning 21,000 decisions and one behavioral experiment (Ns = 1,500; 2,000; 1,600; quota-matched to national demographics in the U.S.), we show the relative and combined influence of government bodies, scientific experts, industry stakeholders, and public consensus in driving responses to 12 issues across environmental, health and technology domains. Across domains, support from scientists and social consensus was most influential in shaping decisions about which solutions are preferable, and influencing behavior like donations to a cause. These effects held even when the government and industry opposed the actions proposed. Together, scientists and the public can mobilize action on contemporary societal challenges, even amidst systemic inaction or opposition.