A Carbon Tax decks political capital.
Aldy 20 (Joseph, is Fellow at Resources for the Future in Washington, DC. He also served on the staff of the President's Council of Economic Advisers, where he was responsible for climate change policy from 1997 to 2000. Winter 2020 “Carbon Tax Review and Updating: Institutionalizing an Act-Learn-Act Approach to U.S. Climate Policy” https://www.journals.uchicago.edu/doi/full/10.1093/reep/rez019)//BH-NB//
The updating of a carbon tax would require a congressional vote and thus the mobilization of political capital for a potential legislative battle every 5 years. For reasons unrelated to climate policy, the president may opt not to initiate such a battle and thus decide against proposing a tax update. Moreover, future Congresses may be more or less inclined to vote for a change in the carbon tax in response to a given change in information. This means that political factors—which are distinct from the results of the environmental, economic, and multilateral reviews—may determine the evolution of carbon tax rates over time. In such cases, the resulting carbon tax rates may be inconsistent with the objective of maximizing social welfare and/or inadequate to achieve long-term climate change goals.