The Census Bureau's release of the first figures from the 2010 Census on December 21, 2010, shifted 12 seats among 18 states for the 113 th Congress (beginning in January 2013). Illinois, Iowa, Louisiana, Massachusetts, Michigan, Missouri, New Jersey, and Pennsylvania each lost one seat; New York and Ohio each lost two seats. Arizona, Georgia, Nevada, South Carolina, Utah, and Washington each gained one seat; Florida gained two seats, and Texas gained four seats. The reapportionment of House seats in 2010 was based on an apportionment population that is different from the actual resident population of each state. For apportionment purposes since 1970 (with the exception of 1980), the Census Bureau has added to each state's resident population the foreign-based, overseas military and federal employees and their dependents, who are from the state but not residing therein at the time of the census. In 2010, these additional persons increased the census count for the 50 states by 1,042,523, a little less than twice the number in 2000. If the foreign-based military and federal employees had not been included in the counts, there would have been no change in the 2010 apportionment of seats, although the order of seat assignment would have changed. The reapportionment process for the House relies on rounding principles, but the actual procedure involves computing a "priority list" of seat assignments for the states. The Constitution allocates the first 50 seats because each state must have at least one Representative. A priority list assigns the remaining 385 seats for a total of 435. Table 2 displays the end of the "priority list" that would be used to allocate Representatives based on the 2012 Census estimates of the state populations as of July 1. The law only provides for 435 seats in the House, but the table illustrates not only the last seats assigned by the apportionment formula (ending at 435), but the states that would just miss getting additional representation. The apportionment counts transmitted by the Census Bureau to the President (who then sends them to Congress) are considered final. Thus, most states that lost seats in the 113 th Congress had only one possible option for retaining them: urge Congress to increase the size of the House. Any other option such as changing the formula used in the computations, or changing the components of the apportionment population (such as omitting the foreign-based military and federal civilian employees) might only affect a small number of states if the House stays at 435 seats. As noted above, the 435-seat limit was imposed in 1929 by 46 Stat. 21, 26-27. Altering the size of the House would require a new law setting a different limit. Article I, Section 2 of the Constitution establishes a minimum House size (one Representative for each state), and a maximum House size (one Representative for every 30,000, or 10,306 based on the 2010 Census). In 2013, a House size of 468 would be necessary to prevent states from losing seats they held from the 108 th to the 112 th Congresses, but, by retaining seats through an increase in the House size, other states would also have their delegations become larger. At a House size of 468, California's delegation size, for example, would be 56 instead of 53 seats. The apportionment figures released on December 21, 2010, are made up of three components: total resident population figures for the 50 states and the District of Columbia, the foreign-based military and overseas federal employees allocated to each state and DC, and the sum of these numbers (excluding DC), which becomes the apportionment population. These numbers (minus DC) are all that is needed to reapportion the House, but most states need figures for very small geographic areas in order to draw new legislative and congressional districts. The Census Bureau must provide small-area population totals to the legislatures and governors of each state by one year after the census (e.g., April 1, 2011). The Census Bureau data delivered by April 1, 2011 (some states started receiving the information in February 2011), are often referred to as the P.L. 94-171 program data (89 Stat. 1023). This program provides, to each state, information from the 2010 Census. As such, the information is very limited--including age, race, and Hispanic origin. No other demographic information that might be useful to the persons constructing political jurisdictions, such as income or employment status, is available in the P.L. 94-171 data. Such data, however, are available from the results of the American Community Survey for geographic areas with populations as small as 20,000 persons. Census data are usually reported by political jurisdictions (states, cities, counties, and towns), and within political jurisdictions by special Census geography (such as Census designated places, tracts, block numbering areas, and blocks). The P.L. 94-171 program allows states, which chose to participate in it (49 in 2010), to request Census data by certain nontraditional Census geography such as voting districts (precincts) and state legislative districts. These special political jurisdiction counts enable the persons drawing the district lines to assess past voting behavior when redrawing congressional and state legislative districts. In most states, redrawing congressional districts is the responsibility of the state legislature with the concurrence of the governor. In seven states, Arizona, California, Hawaii, Idaho, Montana, New Jersey, and Washington, a non-partisan or bi-partisan commission is responsible for drawing and approving the plans. Some states have explicit deadlines in law to complete their congressional districting. Most do not, so the effective deadline for the legislatures or commissions to complete their work would have been whatever deadlines were established in the states for filing for primaries for the 2012 elections. Although many states have standards mandating equal populations, compactness, contiguousness, and other goals to not split counties, towns, and cities, federal law controls the redistricting process. Other than a requirement that multi-member states cannot elect Representatives at-large (2 U.S.C. 2c) however, no federal statutory law establishes explicit standards for redistricting. The principal laws that apply are the Supreme Court decisions mandating one person, one vote and the Voting Rights Act. The fundamental federal rule governing redistricting congressional districts, one person, one vote , was promulgated by the Supreme Court in Wesberry v. Sanders (376 U.S. 7, 1964). The Court has refined that ruling in a series of cases culminating in Karcher v. Daggett (462 U.S. 725, 1983) that one person, one vote means that any population deviation among districts in a state must be justified, but the deviations from absolute equality may be permitted if the states strive to make districts more compact, respect municipal boundaries, preserve the cores of prior districts, or avoid contests between incumbents. Section 2 of the Voting Rights Act (VRA) applies nationwide. It prohibits states or localities from imposing a "voting qualification or prerequisite to voting or standard, practice or procedure ... in a manner which results in the denial or abridgement of the right to vote on account of race or color." The Supreme Court interpreted the VRA's application to redistricting in a series of cases responding, in part, to the extraordinarily complicated districts created by many states in the 1990s to maximize minority representation (beginning with Shaw v. Reno , 509 U.S. 630, 1993). The Court ended the decade by establishing new principles concerning such practices: (1) race may be considered in districting to remedy past discrimination; (2) but, states must have a compelling state interest to ignore traditional redistricting principles and "gerrymander" to establish majority-minority districts; (3) courts will apply "strict scrutiny" to such assertions that racial "gerrymanders" are necessary to determine whether such plans are narrowly tailored to achieve the compelling state interest.

Summary:
On December 21, 2010, the Commerce Department released 2010 Census population figures and the resulting reapportionment of seats in the House of Representatives. The apportionment population of the 50 states in 2010 was 309,183,463, a figure 9.9% greater than in 2000. Just as in the 108th Congress, 12 seats shifted among 18 states in the 113th Congress as a result of the reapportionment. The next census data release was February 2011, when the Census Bureau provided states the small-area data necessary to re-draw congressional and state legislative districts in time for the 2012 elections. This report examines the distribution of seats based on the most recent estimates of the population of the states (as of July 1, 2012). It explores the question of, what, if any, would be the impact on the distribution of seats in the U.S. House of Representatives if the apportionment were conducted today, using the most recent official U.S. Census population figures available. The report will be updated as is deemed necessary.