The courts are bound by all of decisions of the Supreme Court of the United States.  See Agostini v. Felton, 521 U.S. 203, 237-238 (1997); State Oil Co. v. Khan, 522 U.S. 3, 20 (1997) - "it is this Court's prerogative alone to overrule one of its precedents."

See:

Agostini v Felton

State Oil v Kahn