The API is suggesting that it would support a carbon tax in the US, but at the same time is suggesting that this would only be supported if it was the only mechanism that regulators used at a Federal level. While both Europe and California have carbon taxes, they have many other regulations and mechanisms to help lower emissions, such as credits for EV use and LCSF in California.
In Europe, the Cap and Trade system for CO2 was not well thought through in the early days and grossly underestimated the easy fixes in the system, leading to credits greatly exceeding demand and to very low carbon prices. As Caps have come down in Europe, we are now reaching a point where cheap carbon fixes are behind us and the carbon price has risen rapidly over the last three years and currently sits at around €40 per metric ton, with the expectation that it will go higher
For the cap and trade system to work in the US, or for a tax alone to work, the conditions around the tax may not sit well with the API members and the details may be the stumbling block:
There is much more detail needed around trade and how much of a time exemption you give certain industries to adjust – plus the tax needs to more than cover the cost of monitoring and enforcement. A carbon tax alone (as suggested by the API) could do the job, but the devil is in the details and the details will likely not be as agreeable to the API members today as the broad concept.