I think Professor Rossi nailed it: Part of the question is whether the action is framed as enhancing competition or with the purpose of regulating the environment more broadly, said Jim Rossi, a professor and chair in law at the Vanderbilt University School of Law. "If the argument is 'This is to reduce barriers to competition and to facilitate a competitive market,'Â I think you are squarely in your wheelhouse. But if you're drawing on broader purposes of regulating carbon, to protect the environment, that's where I think [the statute] really does raise the question of whether you have that jurisdiction," according to Rossi.
IMO, a significant majority of the proponents arguments favoring carbon pricing seem to be aimed at reducing carbon emissions and not to enhance competition.