<P> The courts generally do not consider ballot access rules for independent and third party candidates to be additional qualifications for holding office and there are no federal regulations regarding ballot access . As a result, the process to gain ballot access varies greatly from state to state, and in the case of a third party may be affected by results of previous years' elections . </P> <P> In 1967, the United States Congress passed the Uniform Congressional District Act, which requires almost all representatives be elected from single - member - districts . Following the Wesberry v. Sanders decision, Congress was motivated by fears that courts would impose at - large plurality districts on states that did not redistrict to comply with the new mandates for districts roughly equal in population, and Congress also sought to prevent attempts by southern states to use such voting systems to dilute the vote of racial minorities . Several states have used multi-member districts in the past, although only two states (Hawaii and New Mexico) used multi-member districts in 1967 . Hawaii and New Mexico were made exempt from the Uniform Congressional District Act, and are free to use multi-member districts, although neither state chooses to do so . </P> <P> Louisiana is unique in that it holds an all - party "primary election" on the general Election Day with a subsequent run - off election between the top two finishers (regardless of party) if no candidate received a majority in the primary . The states of Washington and California now use a similar (though not identical) system to that used by Louisiana . Seats vacated during a term are filled through special elections, unless the vacancy occurs closer to the next general election date than a pre-established deadline . The term of a member chosen in a special election usually begins the next day, or as soon as the results are certified . </P> <Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (March 2018) (Learn how and when to remove this template message) </Td> </Tr> </Table>

Requirements for senate and house of representatives chart