 Based on the theory that the lower courts are creations not of the Constitution but of Congress, and that Congress therefore has wide power in defining and restricting their jurisdiction, the act forbids issuance of injunctions to sustain anti-union contracts of employment, to prevent ceasing or refusing to perform any work or remain in any relation of employment, or to restrain acts generally constituting component parts of strikes, boycotts, and picketing.It also said courts could no longer enforce yellow-dog contracts, which are labor contracts prohibiting a worker from joining a union.Never an isolationist, he supported using American influence abroad on behalf of democracy or for national independence or against autocracy.