Other states with large Hispanic populations — such as Texas and Arizona — are also projected by Election Data Services (EDS) to gain seats. Congressional seats affecting a total of 18 states are expected to change hands based on results from the 2010 Census.

Douglas Johnson, a fellow at the California-based Rose Institute who studies redistricting, said the most interesting number to come out of the new estimate was for the country's total population.

"The national total is interesting, but since the number of seats in the House is set at 435, all that matters for reapportionment is each state's count relative to the other 49 states. The national total can change, but the size of the House does not," he said in an e-mail to The Ballot Box.

"Some of the ethnic and age breakdown data can be looked at to see if it hints at changes in apportionment for states with relatively high concentrations of those ethnicities or ages, but that is stretching the data much farther than it was meant to be stretched, and unlikely to tell us much of use."

Moreover, these estimates don't factor in some items, such as military personnel.

That means North Carolina or another state with a heavy military presence may get an additional seat, according to EDS.

After the Census is completed at the end of the month, the data will be used by states during congressional redistricting in 2011. 

--Updated at 5:40 p.m.