IN GREEK MYTHOLOGY the chimera was part lion, part goat and part snake, but wholly monstrous. Despite its name, there is a chimerical air to the One Big Beautiful Bill Act (BBB), the Republican tax-and-spending plan lurching through Congress this week. It sutures to a body of government-shrinking Reaganism an appendage of populist Trumpism, both disfigured by carve-outs and fillips for individual lawmakers. It will menace the American economy for at least a decade.