States where Hispanics have settled in large numbers saw some of the highest percent changes in population growth and gained congressional seats, according to the first set of Census 2010 results, released Tuesday.

Many states in the South and West that have been magnets for Latinos saw double-digit percentage growths. The growth in those areas far outpaced the nation's, which saw a population increase of 9.7 percent over the 2000 Census count of 281 million residents.

The new national population is 308.7 million.

This first release of Census results did not include data on race or ethnicity -- reports with those details will be released early next year. But many demographic experts have been expecting the 2010 Census to show that some of the largest growth in population would occur in states that are home to Hispanics, who have a higher birthrate than most other groups and include millions of immigrants.

Nevada, where Latinos were a significant factor in the re-election of Sen. Harry Reid, a Democrat, saw a 35 percent population increase, the highest of any state. Nevada gained one congressional seat.

Texas saw a 21 percent growth, and gained four seats - coming out the top winner in gains in congressional representation. The gain in Texas, particularly, has been attributed by demographic experts in large measure to its growing Hispanic population and an economy that weathered the recession.

Florida, with an 18 percent growth, was the second winner in apportionments with two more seats.

Arizona, which in the last year became an immigration policy battleground with its controversial measure empowering police to check for immigration status, had a population growth of 9.1 percent, and will gain one seat.

Puerto Rico saw a decline of 2.2 percent.

The results were released in Washington by Census officials Tuesday morning.

The 2010 Census was a massive undertaking," said Rebecca Blank, Acting Deputy Secretary of Commerce, "and in reporting these first results, we renew our commitment to our great American democracy peacefully, fairly and openly for the 23rd time in our nation's history."

In answer to questions by reporters at a press conference in Washington D.C. about how much of the growth in certain states could be traced to immigrants, Census officials said they could not know for sure, citing that ethnicity data had not yet been put together.

But many others connected the dots between the data and Latinos.

"The results from the U.S. Census confirm that the states with a heavy Hispanic population are the 'winners' in terms of the number of house seats gained," said Joe Kutchera, an expert on demographic trends and author of "Latino Link: Building Brands Online with Hispanic Communities and Content." "The growth in the U.S. is centered in the South and Southwest, regions that are heavily Hispanic."

"And the five most populous states [are] geographic areas that point to the growth of the U.S. coming from the Hispanic population."

Today's official count will be used to reapportion state legislatures and the House of Representatives, and to divide up federal aid to states.

The continued growth of the Hispanic population is likely to offset declining immigration when it comes to redrawing legislative districts next year, say election experts.

Census estimates released recently showed that lower rates of immigration in recent years seem to have contributed to a lower than expected total U.S. population.

That raised questions about whether the decline in immigration - believed to be fueled by high unemployment, making the U.S. less alluring - would mean a loss of political power for Hispanics if states where they live in large numbers lose congressional seats or consider them less of a factor when they reconfigure legislative districts after the release of the 2010 Census results.

But experts on elections and demographics stress that even with a slower growth in immigration, the Hispanic population - which is more than 60 percent native-born - continues to soar.

That is why states such as Texas, Florida and Arizona, which have among the nation's largest Hispanic populations, were expected to see growth and gain seats. And the Hispanic and immigrant population is also why, others believe, some states, like New York, which lost two seats, and Pennsylvania, which lost one, did not lose even more.

"Immigration is just one part of the story of the Hispanic population," said Rosalind Gold, senior director of policy, research and advocacy for the National Association of Latino Elected and Appointed Officials, or NALEO. "We have to see what the 2010 Census shows about their total population, what states they are moving to."

Hispanics number about 45 million, or 15 percent of the population. That is an increase of 10 million over the 2000 total of 35.6 million.

A recent Census estimate showed that Hispanics accounted for all the growth in the nation's youth population in the last decade. Hispanics who are 20 years old and younger make up one out of every four people in that age group, the estimate said.

That suggests a huge potential for a greater political voice for Hispanics, as they turn 18 and become eligible to vote, Gold said.

"It will be very important that those kids who become voters have a chance for their voices to be heard when they choose their elected representatives."

State legislative and congressional district boundaries are redrawn every 10 years by state officials following the decennial census.

"The impact [of the 2010 Census findings] will be determined by the Latino community," said Gloria Montaño-Greene, NALEO's Educational Fund Washington Director. "Their participation in the next step, the creation of legislative maps and how the maps uphold the Voting Rights Act, and the inclusion of the Latino population" in the whole process."