<P> A common misperception is that the Supreme Court is the only court that may determine constitutionality; the power is exercised even by the inferior courts . But only Supreme Court decisions are binding across the nation . Decisions of a Court of Appeals, for instance, are binding only in the circuit over which the court has jurisdiction . </P> <P> The power to review the constitutionality of laws may be limited by Congress, which has the power to set the jurisdiction of the courts . The only constitutional limit on Congress' power to set the jurisdiction of the judiciary relates to the Supreme Court; the Supreme Court may exercise only appellate jurisdiction except in cases involving states and cases affecting foreign ambassadors, ministers or consuls . </P> <P> The Chief Justice presides in the Senate during a president's impeachment trial . The rules of the Senate, however, generally do not grant much authority to the presiding officer . Thus, the Chief Justice's role in this regard is a limited one . </P> <Table> <Tr> <Td> </Td> <Td> This section possibly contains original research . Please improve it by verifying the claims made and adding inline citations . Statements consisting only of original research should be removed . (February 2015) (Learn how and when to remove this template message) </Td> </Tr> </Table>

Where did the writers of the united states constitution find out about seperation of powers