Section 1 begins with a vesting clause that confers federal executive power upon the president. Similar clauses are found in Article I and Article III; the former bestows federal legislative power exclusively to Congress, and the latter grants judicial power solely to the Supreme Court, and other federal courts established by law. These three articles together secure a separation of powers among the three branches of the federal government, and individually, each one entrenches checks and balances on the operation and power of the other two branches.