Census data released Tuesday reflects how illegal immigration could shape the makeup of Congress, with border states and other immigration magnets registering big gains over the past decade.

Though the latest Census Bureau information does not include breakouts on race or ethnicity, Western and Southern states with large, or at least growing, immigrant populations were generally the ones that gained enough new residents to warrant additional congressional seats.

Illegal immigrants would constitute just one of several factors in the population shifts recorded in that time. But since illegal immigrants are counted in the U.S. Census by law, they have an inevitable impact on the way House seats are divvied up.

"You can see how they can have a big impact on the distribution of seats," said Steven Camarota, research director with the Center for Immigration Studies. "Michigan and Pennsylvania are going to lose a seat and it's going to go to some other place ... because of the inclusion of illegal immigrants."

Camarota estimated the total number of illegal immigrants counted in the 2010 Census at about 10 million. Total population growth for immigrants in the United States exceeded 13 million over the last 10 years. With the U.S. population at 309 million, that might sound like a drop in the melting pot. But their numbers start to make a difference on a state-by-state level.

Several states with large immigration populations, both legal and illegal, will gain at least one seat out of the latest census numbers. They include Florida, Texas, Arizona and Nevada. South Carolina, Georgia and Washington state, which all saw unusually high rates of growth in their immigrant populations over the past decade, will also gain a congressional seat each. South Carolina, for instance, registered a 150 percent increase in its immigrant population, according to a CIS analysis.

Camarota said that regardless of whether the changes are coming from influxes of illegal or legal immigrants, more districts are going to be created with swaths of people in them who can't vote.

"Literally we'll have districts like we have right now where half the adult population can't vote," he said. He said the impact they have on the drawing of congressional seats raises "profound and important questions."

Officials from both parties, though, welcomed the census numbers Tuesday. The Democratic Congressional Campaign Committee said the growth in their constituencies -- Hispanics are a key Democratic voting bloc -- "pours cold water" on warnings that the census results would reinforce GOP gains from the last election. Republicans, likewise, grinned at the overall population shift to conservative-leaning states -- disregarding, perhaps, the factor illegal immigration may have played in that trend.

Rep. Steve King, R-Iowa, was not among them. The firebrand congressman told FoxNews.com the census underscores the need to examine the counting of illegal immigrants -- something he thinks should not be done.

"We need to drill into it and drill into it deeply," he said, arguing that the founders did not envision giving congressional representation to those in the United States illegally.

Camarota, though, said there's little Washington can do to change how the census is conducted since the bureau is constitutionally mandated to complete a nationwide head count of all residents. He said lawmakers should be concentrating on border enforcement instead.

The border debate, though, may continue to take a backseat to proposals that would bring undocumented residents already here out of the shadows and into the fold of society.

The White House said Tuesday that President Obama, who met with members of the Congressional Hispanic Caucus, is not giving up on the so-called DREAM Act. The bill, which failed on a vote in the Senate over the weekend, would give some illegal immigrants who go to college or join the military a path to legalization. Obama also called for a broader immigration reform package.

Members of the Congressional Hispanic Caucus said in a statement Tuesday that it is "disillusioning" to see Republicans who once supported the DREAM Act turn against it in the current climate. They expressed concern not about the number of immigrants entering the country but about the number being forced out.

"At the current rate, another 800,000 people will be deported by the time November 2012 comes around, which does nothing to fix our immigration system and rips apart communities and families and the very fabric of our society," the statement said.