This study investigates the role of climate change contrarians in the defeat of the American Clean Energy and Security Act in 2010, a pivotal moment in U.S. climate policy that marked the end of extensive efforts to enact cap-and-trade climate legislation in the United States. Our research objectives are twofold: firstly, to determine the extent to which climate contrarians gained access to testify at congressional hearings in the years leading up to the bill’s ultimate defeat; and secondly, to examine the potential influence of fossil fuel industry (FFI) funds in facilitating this access. We compile a comprehensive new dataset encompassing all witnesses testifying at cap-and-trade and climate science hearings from 2003 to 2010. This information is cross-referenced with other pertinent data concerning interest groups, lobbying activities, and Congress. Our findings reveal a significant correlation between FFI lobbying expenditures and campaign contributions and the presence of contrarian witnesses at these hearings, suggesting a coordinated effort by the FFI to obstruct climate legislation. We find that contrarians were able to obtain disproportionate access to central hearings in key committees with jurisdiction over cap-and-trade bills, increasing their potential to obstruct legislation. Moreover, our analysis exposes a concerning over-representation of scientists known to deny the scientific consensus at these hearings, undermining the scientific consensus on climate change and perpetuating doubt about the urgency of climate action.