Who decides if the US Supreme Court can be given further original jurisdiction?

Answer

The Supreme Court's jurisdiction can only be expanded by Constitutional amendment; however, Congress can engage in jurisdictional stripping, in which authority to hear certain types or classes cases not specified in Article III, Section 2, can be denied*.

* (One example is Congress, under the Bush Administration, revoking the Court's right to adjudicate writs of habeas corpus for Guantanamo detainees. This legislation has since been declared unconstitutional because the substitute procedure denied prisoners' due process.)


Explanation

Either the Senate would have to introduce a bill, or the House would have to introduce a resolution, that received a two-thirds vote of both houses of Congress. The proposed amendment would then be sent to the states for ratification. If three-quarters of the states (actually 39 states) ratify the amendment within the prescribed time frame (7 years is typical), then the Constitution could be modified to change the Supreme Court's jurisdiction.

This issue was addressed in Marbury v. Madison, (1803), when the Marshall Court declared Congress had overstepped its Constitutional authority by attempting to add responsibility for writs of mandamus (a court order compelling an official to act - or refrain from acting - on something over which the official has legal responsibility) for US government officials in the Judiciary Act of 1789. The Court declared Section 13 of the act unconstitutional, nullifying that part of the legislation.

In contrast, Congress successfully revoked the Supreme Court's original jurisdiction over disputes between a state and citizens of another state (Article III, Section 2), by collaborating with the States to pass the Eleventh Amendment. This was done in response to the Court's decision in Chisholm v. Georgia, (1793), when the Jay Court decided states lacked sovereign immunity from civil suits brought by citizens for debt incurred during the Revolutionary War.

"The judicial power of the United States shall not be construed to extend to any suit in law or equity, commenced or prosecuted against one of the United States by citizens of another state, or by citizens or subjects of any foreign state"