Nuclear option

The nuclear, or constitutional, option is a parliamentary procedure that allows the United States Senate to override its own rules by majority vote. Senate rules require a three fifths, or 60 vote, "supermajority" to reach a decision in many situations. If the presiding officer rules that a motion raises a constitutional issue, the matter then goes immediately to the full senate. Since the Senate decides a constitutional issue by majority vote, this procedure may be used to bypass any requirement for a supermajority. In general, the presiding officer follows precedent as interpreted by the parliamentarian. Unlike the Speaker of the House, he rarely uses his discretionary power.

In 1892, the U.S. Supreme Court ruled in United States v. Ballin that the House of Representatives is a parliamentary body and as such may established rules by majority vote. These rules may not violate fundamental rights or constitutional restraints, according to this opinion. It has been argued that Ballin does not apply to the Senate because the Senate is in continuous session. However, Vice President Richard Nixon, writing as president of the Senate, extended Ballin to the upper chamber in an opinion issued in 1957. Nixon stated that the constitution grants the presiding officer the authority to disregard Senate rules, provided that his ruling is later upheld by majority vote. This procedure was used in 1975 to reform the filibuster. Senator Trent Lott gave it the name "nuclear option" in 2003. The procedure was used again in November 2013 to revise rules concerning judicial and administrative nominations. Except for supreme court justice, these may now be confirmed by majority vote.