congress must reapportion seats in the house of representatives after how many years
United States congressional apportionment Though the actual reapportionment will normally occur in respect of a decennial census, the law that governs the total number of representatives and the method of apportionment to be carried into force at that time can be created prior to the census.
Article Five of the United States Constitution Article V provides two methods for amending the nation's frame of government. The first method authorizes Congress, "whenever two-thirds of both houses shall deem it necessary" (a two-thirds of those members present—assuming that a quorum exists at the time that the vote is cast—and not necessarily a two-thirds vote of the entire membership elected and serving in the two houses of Congress), to propose Constitutional amendments. The second method requires Congress, "on the application of the legislatures of two-thirds of the several states" (presently 34), to "call a convention for proposing amendments".[5]
Electoral College (United States) A state's number of electors equals the number of representatives plus two electors for both senators the state has in the United States Congress.[43][44] The number of representatives is based on the respective populations, determined every 10 years by the United States Census. Each representative represents on average 711,000 persons.[45]
Article One of the United States Constitution The purpose of this clause is twofold. First, it makes clear the division of responsibility with respect to the conduct of the election of federal Senators and Representatives. That responsibility lies primarily with the states and secondarily with Congress. Second, the clause lodges the power to regulate elections in the respective legislative branches of the states and the federal government, not with the executive or judicial.[45][46] As authorized by this clause, Congress has set a uniform date for federal elections: the Tuesday following the first Monday in November.[47]