The estimates of state-by-state population as of July 2008, released Monday by the U.S. Census Bureau, show a decades-long pattern continuing apace: Growth in the nation’s Southern and Western states continues to out-distance that in the states of the Northeast and Midwest.

And unless this trend is drastically altered before the actual once-a-decade census is conducted in April 2010, those sun-kissed areas will make yet another gain in political clout — in the form of U.S. House seats transferred from the Frost Belt in the post-census reapportionment.

That is the conclusion of a study by Election Data Services (EDS), also issued Monday, which makes annual projections of the next congressional reapportionment based on the Census Bureau’s population estimates.

Based on its analysis, EDS says Texas would be the big winner among the six states that would gain House seats, with three added to its current 32. If that occurs, Texas — already the nation’s second most-populous state behind only California — would gain multiple House seats for the fourth consecutive decade.

The era of huge population growth for California appears to have peaked, with the EDS projections showing the state holding at 53 House seats. California, which first surpassed long-time population leader New York in the 1970 census, enjoyed a one-seat gain as a result of the 2000 census after taking a huge seven-seat gain in the 1990s. If the projection holds, the 2010 census will be the first that doesn’t produce a House seat gain for California since it achieved statehood in 1850.

The other projected gainers, though, are from among those states that have expanded their congressional rosters in recent years. Arizona, Florida, Georgia, Nevada and Utah would each gain one seat according to EDS’ reapportionment projections.

Of those eight seats that would shift south and west, seven would come from states in the North where thriving industries diminished long before the nation’s economic downturn: Iowa, Massachusetts, Michigan, New Jersey, New York, Ohio and Pennsylvania would each lose one seat.

The only regional anomaly is Louisiana, which also would lose one seat. Burdened by an economy that is overly dependent on the ups and downs of oil and gas production, Louisiana appeared headed toward a one-seat loss even before Hurricane Katrina hit in August 2005. Louisiana’s estimated population declined by more than 250,000 by mid-2006, in the aftermath of that cataclysm, though the state has regained much of that lost population in the two years since.

It must be remembered that the estimates are not official and that the balance can change from year to year. For instance, the EDS estimates last year showed Texas likely to gain only two seats and Missouri losing one, while Michigan and New Jersey were projected to hold even at their current delegation numbers

While EDS applies the complicated mathematical formula for reapportionment to the data in the Census Bureau estimates, its analysts also try to envision what changes there might be by decade’s end based on the trends from the most recent surveys. And those trends, according to EDS, suggest the Frost Belt to Sunbelt shift could end up being even more profound. If the 2007-08 population trends continue, says the consulting firm, eight states would gain seats — including Texas with four and Arizona with two — while Ohio, with a two-seat loss, would top a list of 10 other states losing a seat apiece.

“With the housing market downturn in the past two years, the onset of the recession this year and an ever-decreasing time before the actual census, there are indications that the most immediate changes may well form the best clues of what we could find in 2010,” Kimball Brace, president of Election Data Services. Inc., noted in a statement.

He also said there are places such as Oregon and Washington that are gaining population, which could help their chances to gain seats in two years. He cited the temperate weather and beautiful environment in the Northwest as possible reasons.

The Census Bureau estimates showed Utah as the fastest growing state between July 2007 and July 2008, overtaking Nevada, which was the fastest-growing state last year. In general, the West was the fastest-growing region percentage-wise, while the already populous South gained the most new residents in raw numbers.