The Supreme Court has the ability to decide whether any law--whether a federal or state law--is constitutional or not.
The Supreme Court is asked to review more than 7,000 cases each year, of which it agrees to hear about 100 to 150 cases per year. The vast majority of those cases work their way up to the Supreme Court from lower courts. About two-thirds of the cases come from lower federal court decisions that are appealed for review, and about one-third of the cases are reviewing decisions made by supreme courts of individual states. But there are some cases that can have original jurisdiction at the Supreme Court level -- such as when there is a case between one state government and another or between state governments and the federal government.
Although the supreme court sets precedents for all courts, they only do this for Federal Matters and Constitutional interpretations. Each state has their own supreme court. A supreme court precedent can be refered to in a local court.
