The supreme court can declare laws and actions by the executive branch unconstitutional and the legislative branch must give its consent to the president's appointment federal judges, ambassadors, and the heads of executive departments.
The president exercises a check over Congress through his power to veto bills, but Congress may override any veto (excluding the so-called "pocket veto") by a two-thirds majority in each house. ... The President is not mandated to carry out the orders of the Supreme Court.
