Assuming census estimates turn out to be true just eleven months from now, there will be a switch of 13 House seats from some states to others, confirming further the trend since 1950 of a population boom in the Sunbelt (South and West), and a relative population decline percentage wise in the Rust Belt (Northeast and Midwest).
The big winner would be Texas with four seats, followed by Arizona with a two seat gain. Also gaining one seat each would be Florida, Georgia, South Carolina and North Carolina in the South; and Nevada, Utah, and Oregon in the West.
A surprise is that California seemingly will lose one seat, after decades of constant and rapid growth. Louisiana would also lose, partially but not totally due to the effects of Hurricane Katrina. These are the only Western and Southern states that would lose seats in the House and in electoral votes. The others are states in the Northeast, including New York, New Jersey, Pennsylvania and Massachusetts, each losing one seat; and in the Midwest, two seats lost in Ohio, and one each in Illinois, Iowa, Michigan, Minnesota and Missouri.
So altogether, if trends stay as they are now, nine states would gain seats and twelve states would lose seats. It should not hurt the Democrats, however, as younger and Hispanic voters are major backers of the Democrats and will have a growing influence in many of the states that are gaining congressional seats.