Continued robust population growth signals a potential surge in political power for Southern states into the foreseeable future.

Census state population estimates released Tuesday show that Florida, North Carolina and Texas would each gain one seat in the House of Representatives if reapportionment happened today. (Oregon in the Northwest would as well.)

If population trends continue through 2020, when redistricting occurs, Texas would gain three seats, Florida two and Arizona, Colorado and North Carolina and Oregon one each.

The estimates, from July 1, 2015, also include figures for the voting-age population. Conservatives are asking the U.S. Supreme Court, in Evenwel v. Abbott, to change state laws so congressional districts would be based not on total population but on the number of citizens eligible to vote. If representation were based on the number of voters, Texas would lose one seat.

“That’s the most intriguing thing,” said Kimball Brace, the president of Election Data Services, who analyzed the potential impact of the new numbers on long-term political calculus. The high court and its interpretation of the Constitution stands in the way of any shift in apportioning the 435 congressional districts.

On the basis of the number of eligible voters, Florida, North Carolina and Oregon would each gain a seat. in addition to Texas, Illinois and Minnesota and would each lose one.

The Supreme Court has heard arguments in Evenwel v. Abbott and is expected to issue its ruling in June.

Districts with large immigrant populations that tend to be younger and include more noncitizens and minors are bound to be affected if reapportionment is based on eligible voters rather than the one-person, one-vote standard in place since a 1964 Supreme Court ruling.

As long as total population continues to be the foundation for deciding districting, Southern states win.