<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>
what is reapportionment and when does it take place
following each decennial census census changes the state 's number of Representatives require states to redistrict based on each census