The proposal, which had been called a "compromise" bill by Republicans, would have provided some respite to youth brought to the country illegally as minors, as well as some $25 million in funding for part of a wall along the border with Mexico.
The 5-4 decision fulfills a longtime wish of conservatives to get rid of the so-called fair share fees that non-members pay to unions in roughly two dozen states. The court ruled that the laws violate the First Amendment by compelling workers to support unions they may disagree with.