IF YOU want to put a policymaker on the spot, ask them what the top rate of income tax should be. The question befuddles everyone. On May 8th President Donald Trump broke with decades of Republican convention when he reportedly urged Mike Johnson, the speaker of the House of Representatives, to increase America’s highest federal levy on incomes from 37% to 39.6%, where it stood before the president’s own reforms in 2017. Mr Trump then took to social media to announce that although he would “graciously accept” such a change “in order to help the lower and middle income workers”, Republicans in Congress “should probably not do it”. He is nevertheless “OK if they do”.