An interstate trucking company filed suit against the state of Michigan, alleging that Michigan's $100 annual fee on trucks involved in intrastate commerce violates the dormant commerce clause. The trucking company argued that the fee discriminates against trucks involved in both intrastate and interstate commerce because they spend less time carrying cargo in Michigan than do trucks involved with solely intrastate commerce. The state argued that the fee is a valid exercise of its police power, intending to defray the costs of regulating the size and weight of trucks in Michigan. With whom do you think the U.S. Supreme Court sided in this case? Why?