When running for president, one of Donald Trump’s “big league” promises was to lower the corporate tax rate to a flat 15%. Part of the thinking behind the proposal is that lowering the corporate tax rate will entice corporations considering leaving the country to stay and give American companies a more level playing field to compete with the rest of the world. In early February, Trump reiterated this idea, saying that his administration would soon be announcing something “that will be phenomenal in terms of tax.”