Lin Sing v. Washburn, 20 Cal. 534 (1862)

nIt must be admitted that the act before us is a measure of special and extreme hostility to the Chinese, and that the power asserted in its passage is the right of the State to prescribe the terms upon which they shall be permitted to reside in it. This right, if carried to the extent to which it may be carried if the power exists, may be so used as to cut off all intercourse between them and the people of the State, and obstruct and block up the channels of commerce, laying an embargo upon trade, and defeating the commercial policy of the nation. The act is sought to be maintained as a police regulation; but this branch of the police power has been surrendered to the government as a part of the power to regulate commerce, and its exercise by a State is incompatible with the authority of the government.