Six states including Texas and Florida will gain seats in the US House of Representatives when congressional districts are redrawn this year under new census data that underscored the growing political influence of sunbelt states.

The Census Bureau on Monday released population data based on the 2020 census, a sweeping nationwide survey conducted once every 10 years. The figures showed the US population rose to 331,449,281 in 2020, a 7.4 per cent increase since 2010, when the previous census was conducted.

The data illustrated how quickly some parts of the country have grown relative to others over the past decade. The population grew 10.2 per cent in the south from 2010-20, compared with 9.2 per cent growth in the west, according to the Census Bureau. The north-east’s population grew 4.1 per cent, while the Midwest grew 3.1 per cent over the same 10-year period.

The numbers hold political significance because they will be used to reallocate the 435 congressional districts ahead of next year’s midterm election, when every seat in the House of Representatives will be up for grabs. Democrats control the House by a margin of just six seats.

The Census Bureau said that because of the latest population shifts, six states — Texas, Colorado, Florida, Montana, North Carolina and Oregon — will gain seats in the House. Seven — California, Illinois, Michigan, New York, Ohio, Pennsylvania and West Virginia — will each lose one.

Texas was the only state that will gain two representatives when congressional district lines are redrawn; the other five will each gain one.

map showing US states that will gain or lose Congressional seats as a result of the 2020 Census population counts.Colorado, Florida, Montana, North Carolina and Oregon will each gain one seat in the House. California, Illinois, Michigan, New York, Ohio, Pennsylvania and West Virginia will each lose one seat. Texas will gain two seats.

US House seats are reshuffled every 10 years to account for shifts in the population so that congressional districts represent roughly the same number of constituents. States gain or lose seats depending on the relative growth of their populations over the preceding decade, based on census data.

The latest figures underscored the growing political clout of states in the south and west and the waning influence of those in the north-east and Midwest. In the short term, the changes could provide a boost to Republicans, who have performed better in recent elections in the states that stand to gain seats.

The data also set off the highly fraught redistricting process, in which the boundaries for each congressional district are redrawn, either by state legislatures or independent commissions. Redistricting can be a highly partisan process, in which parties in power redraw electoral maps to their own advantage.

Additional reporting by Christine Zhang in New York