Apportionment

1960–2010 Reapportionment Shifts

The number of Congressional seats has remained virtually* constant at 435 since a federal statute set the number in 1911.

Though the number of seats has not changed, the movement of seats has. Over the past five reapportionments, 62 seats shifted south and west; nearly as many as the 65 seats first apportioned by the Constitution.

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The Losers

In all, the mid-Atlantic, New England, Great Lakes, and Midwest regions have seen 62 seats washed away to the south and the west. The mid-Atlantic region lost 27 seats over the fifty-year span, New England lost four, the Great Lakes states dropped by 23 and the Midwest lost eight.

Losses have been heaviest in the states bordering Lake Erie and Lake Michigan, with 46 seats reapportioned over the five decades.

Virginia is the only state in these four regions to have gained a seat in the past fifty years, regaining its 11th district in 1990.

The Gainers

Over the same period the South has gained 29 seats, driven in large part by huge growth in Florida, having gained 15 seats, and Texas’ 13 seat gain. . Outside Texas, seat increases in the South have been contained to states bordering the Atlantic Ocean. Georgia and North Carolina are two such examples, picking up four and two seats respectively over the past five reapportionments. Other states in the region have either maintained or lost seats.

The Mountain West has seen exponential growth as well. Arizona increased by six seats, Colorado by three, Nevada by three, and Utah by two. Nevada’s gains were most notable, having quadrupled its representation – jumping from one to four seats. Arizona’s representation tripled from three to nine, and Utah doubled from two to four.

The Pacific states have gained 19 seats with California accounting for 15 of them.

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The Biggest Losers and Gainers

California and Florida were the biggest winners, gaining 15 seats respectively. Texas added 13 seats; Arizona added six while Georgia gained four.

State Net Seat Gain
California +15
Florida +15
Texas +13
Arizona +6
Georgia +4

New York suffered the most losses over the 50-year period, with a 14 seat drop. Pennsylvania lost nine seats, Ohio eight, Illinois six, and Michigan five.

State Net Seat Loss
New York -14
Pennsylvania -9
Ohio -8
Illinois -6
Michigan -5

If Our 2018 Apportionment Projections Hold

Our 2018 Apportionment Projections anticipate a continuation of the half-century trend. The South stands to gain another five seats and the Mountain West three. The Pacific states could end up breaking even if Oregon gains seats while California loses. The Mid-Atlantic is poised to lose at least three, while New England drops one. The Great Lakes states could give up four more.

Those results would reshuffle the long-term standing of states with the highest gains. Texas would jump from third to second with a net of 16 seats. In turn, California would drop from first to third, gaining 14 seats behind Florida’s 17. Arizona would stay fourth with seven seats, while Georgia would pull fifth with a gain of four.

State Projected Net Seat Gain
Florida +17
Texas +16
California +14
Arizona +7
Georgia +4

The top five losing states would not change; all five are set to lose again this decade. New York is projected to drop 15 seats, Pennsylvania 10, Ohio nine, Illinois seven, and Michigan six.

State Projected Net Seat Loss
New York -15
Pennsylvania -10
Ohio -9
Illinois -7
Michigan -6

*There were 437 members from 1959-1963 to accommodate the newly added states of Hawaii and Alaska.