<P> Senators from each state were originally elected by that state's legislature, and influenced only indirectly by the voters, through their election of state legislators . The 17th Amendment, ratified in 1913, provided for direct election of U.S. Senators . It did not however, change the principle of equal representation of the states in the Senate, which, as James Madison noted in The Federalist No. 39, ensures a polity of mixed sovereignty, one in which the states are an integral part of the federal government . This, of course, is precisely why those who do not think the Constitution not democratic enough would wish to remove that portion of the Constitution . The 38 million people who live in the nation's 22 least populous states are represented by 44 senators, while the 38 million residents of California, the most populous state, are represented by two . </P> <P> The House of Representatives, by comparison, is required by Article I, Section 2, to be "apportioned among the several states...according to their respective numbers ." The Constitution does not provide for either fractional votes nor Congressional seats spanning states, and guarantees every state at least one Representative . Thus, a resident of a state whose population just barely qualifies for two Representatives has almost twice the relative influence as a resident of a state that does not quite qualify for two . </P> <P> 2 U.S.C. § 2a, based on the Reapportionment Act of 1929, reapportions the Representatives to the states following each decennial census . It left the states to decide how and whether to redistrict, except in the case that the census changes the state's number of Representatives, but federal court cases now require states to redistrict based on each census . </P> <P> However, here too, other criteria take precedence over exact equality of representation . In 2012, the Supreme Court endorsed Tennant v. Jefferson County the use of other criteria, including the legislature's reluctance to move voters between districts, to put incumbent Congressmen in the same district, and to divide counties between districts, when the State of West Virginia redrew its three Congressional districts with a disparity of 0.79% between the most populous and least populous district . </P>

What is reapportionment and when does it take place