This 2020 report from the Institute for Policy Integrity holds that, in the absence of legislation, critical long-distance transmission can be developed by applying existing federal legal authorities. New long-distance, high-voltage transmission lines will be vital if the United States is to deploy enough renewable generation capacity to decarbonize the power sector and to integrate it cost-effectively, as well as electrify our economy in time to meet the targets established in the Paris Agreement. Because Congress may not take timely action to remove barriers to these power lines, this paper seeks to explain steps that the federal government—particularly from within the US Department of Energy (DOE) and Federal Energy Regulatory Commission (FERC) — could take to facilitate development of a future grid that is capable of supporting a reliable, affordable, and increasingly zero-carbon power sector. Acknowledging that state siting requirements may prove an obstacle to developing an efficient, national transmission grid, this paper examines legal authorities already available to DOE and FERC to develop the interstate transmission capacity crucial to the energy transition.