Elon Musk said he’s carrying out his threat to form a new political party after his fissure with President Donald Trump, announcing on social media that he would form the America Party in response to the president’s sweeping tax cuts law.

President Trump and Republicans’ tax law is one of the most significant pieces of health care legislation since the ACA. It centers on this very regressive tradeoff: Poor and middle-class workers will lose their health coverage, while affluent households will reap the largest benefits of tax cuts.