Illegal immigration is not a topic that often comes up when national politicians visit Virginia. So it was something of a surprise to hear President Barack Obama address it so forcefully during a speech in Virginia Beach in the middle of the month.

“Mr. Romney says that undocumented workers in this country should self-deport,” the president said of the presumptive Republican nominee. “My belief is that we are a nation of laws and a nation of immigrants, and I want to make sure that we get comprehensive immigration reform that gives young people who’ve been raised here a chance to live out their own American dream.”

Although border states, especially those next to Mexico, have been grappling with illegal immigration for decades, the question has emerged over the past decade in places — as diverse as Virginia’s Prince William County and Pennsylvania’s Hazleton — that until recently were not magnets for new and undocumented immigrants. Those local concerns have ripened to a point where they have become an issue in many of this year’s Congressional campaigns.

Hispanics accounted for about half the nation’s population increase in the past decade, according to census data. And while half of  the country’s 50.5 million Hispanics live in just three states — Florida, Texas and California — the Hispanic population doubled over the decade in Tennessee, Arkansas, South Dakota and both of the Carolinas.

It remains to be seen whether this increase will translate into a prominent voting force. Despite the growth in population, the number of Latinos registered to vote actually dropped from 11.6 million in 2008 to 10.9 million in 2010, according to the census.

Still, many Democratic Congressional candidates are honing their talking points to appeal to Hispanics. Many, if not most, of them are taking a page from Obama’s playbook and endorsing the administration’s decision this summer to employ “prosecutorial discretion” in not pursuing the deportation of millions of younger illegal immigrants who entered the United States at the behest of their parents but have lived upstanding lives since.

For Republicans running for the House and Senate in competitive races, the calculus is generally much more complicated. They are eager to appeal to Hispanic voters but don’t want to do anything to alienate their political base, which is made up of conservatives who view illegal immigration as more a question of obeying the rule of law than as a matter of social policy. Republican candidates who need to make inroads among Hispanic voters are carrying a different message than those who are wary of rewarding people who live here illegally.

“They’ve put themselves in a real box,” says David Damore, a political science associate professor at the University of Nevada Las Vegas. “You kind of have this disjuncture between the base and these candidates who are maybe thinking about future election cycles.”

Mark Krikorian, executive director of the Center for Immigration Studies, which advocates for less legal and illegal immigration, sees Democrats as being “much more monolithic on immigration” while having to contend with this “internal tension.”

“It creates an internal tension,” he said.

Democrats Benefit From Party Messaging

Many Democratic candidates were quick to praise the president’s June announcement that his administration would allow young people brought to the United States illegally as children to remain in the country and apply for work permits . The policy was modeled on but is more limited in scope than the DREAM Act, which is for now the main legislative goal of the Latino advocacy community. It would put eligible young people on a path to citizenship provided they have no criminal record and are enrolled in school or join the military. The measure has been rejected by Congress on more than one occasion.

Democratic candidates have also drawn encouragement from the Supreme Court’s decision striking down much of the Republican-sponsored illegal immigration law Arizona enacted two years ago, even though its most controversial provision — requiring police officers to check the immigration status of those stopped for another reason — was allowed to stand, at least for the time being.

Democrat Elizabeth Warren, the Massachusetts consumer advocate who is running to unseat Republican Sen. Scott Brown, used the occasion of Obama’s decision to go easy on younger illegal immigrants to lambaste Brown for his 2010 vote against the DREAM Act. “These young people did nothing wrong,” she said. “They should be able to continue living and working here.”

In Virginia’s open-seat Senate race, former Gov. Tim Kaine (D) has recorded ads in Spanish and has repeatedly endorsed the DREAM Act, along with a broader immigration overhaul that would allow the roughly 11 million illegal immigrants currently in the country to gain legal status by paying a fine.

Recent party messaging has been so consistent on this aspect of the debate that it’s easy to forget that less than two years ago, 38 House Democrats voted against a version of the legislation — and then some of the party’s candidates tried to run to the right of their GOP opponents on immigration. One of them was Walt Minnick of Idaho, who accused his Republican challenger, Puerto Rican-born Raul Labrador, of being soft on illegal immigration. (Labrador, a tea party favorite, went on to win by 10 points.)

In 2006, when Democrat Harold Ford Jr., gave up his House seat to run for the Senate in Tennessee, he accused Republican Bob Corker of hiring illegal immigrants to work on the construction sites his company ran.  “To get control of our borders we’ve got to get tough on illegals,” Ford said in a campaign ad. “Let’s also get tough on employers who break the law. Bob Corker disagrees.” (Corker won by 3 points.)

But the demographic shift and Hispanic blowback against tough GOP rhetoric on illegal immigration has likely mattered in some states. Lynn Tramonte, deputy director of America’s Voice, an advocacy group that tracks immigration politics, says Democrats are acutely aware that the Hispanic vote helped propel Western Democrats, such as Senate Majority Leader Harry Reid in Nevada and Michael Bennet in Colorado, to Senate victories against initially long odds two years ago.

How Important Is the Debate?

On the Republican side, candidates are struggling to find a middle ground between Hispanic voters and conservatives who want tough immigration enforcement.

But rather than struggling to resolve it, some candidates have decided to imitate Romney and avoid talking about immigration as much as possible to focus on the economy instead. Voters aren’t likely to hold that against them. Polls show that voters — including Hispanic voters — are more concerned about the economy than any other issue.

“It [immigration] is going to be a sticky wicket. The default position will be to go to the economy,” said Casey Klofstad, a political science professor at the University of Miami. “And it’s a good strategy.”

That’s what Sen. Dean Heller is doing, UNLV professor Damore said. The Nevada Republican, in a tossup fight to keep his Senate seat for a full term against Democratic Rep. Shelley Berkley, has made the economy and questions about Berkley’s ethics a centerpiece of his campaign. Speaking to a Hispanic group in Las Vegas in January, he stressed economic growth, jobs and government regulation rather than immigration. He recently launched a Spanish version of his website that also emphasizes the economy. While the immigration section of his English-language page talks about boosting border security, his Spanish-language site omits references to enforcement and focuses solely on ways to improve the immigration bureaucracy.

The Heller campaign’s spokeswoman, Chandler Smith, says the Senator has been “open and honest” with Hispanic voters about his opposition to the DREAM Act and his support for tougher enforcement. “He is not afraid of this discussion,” she said.

Other GOP candidates are treading carefully as well. Many have fallen in step with Sen. Marco Rubio. The freshman Republican from Florida, a rising star in the party, has accused both sides of inflaming partisan tensions over the issue to win elections rather than earnestly trying to work out a solution. He also spent months this year meeting with lawmakers of both parties in an attempt to craft an alternative version of the DREAM Act that would stop short of offering citizenship.

It was hard not to see the Senator’s influence behind the statements some Republican candidates issued after Obama’s announcement. Many did what Rubio did, criticizing the president’s decision to bypass Congress to implement a new policy, but not being altogether critical of the new policy itself. In Massachusetts, Brown said he would support going further than Obama in one regard, by granting citizenship to young illegal immigrants who serve in the military, but worried the president’s move “would set off a new wave of illegal immigration.”

Eventually, the GOP is going to have to resolve these internal tensions or risk losing the Hispanic vote for a long time, says Nathan Sproul, an Arizona-based Republican political consultant. To him, it will take somebody like Rubio to do it — somebody with unimpeachable conservative credentials who could also appeal to Hispanic voters.

That won’t be easy. A Latino Decisions June poll found 49 percent support among Hispanic voters for Rubio’s limited DREAM Act alternative, but 87 percent for the Democrats’ path-to-citizenship proposal.

“The Republican Party has to develop a plan that is compassionate but yet that also protects our national sovereignty. Right now, most Republicans believe that that’s where the party is, but we need to do a little better job conveying that,” Sproul said. “Until the Republican Party makes that message much more clear, there’s always going to be a danger of reaching a tipping point where Hispanics become permanently aligned with the Democrat Party.”

That is not a universal sentiment among Republicans. Rep. Elton Gallegly, a Californian retiring this year after 13 terms, says candidates should not alter their positions on illegal immigration simply to win Hispanic votes. While polls show voters sympathetic to the plight of illegal immigrant children who would be covered by the DREAM Act, on other immigration issues Republican proposals are popular. A CBS/New York Times poll in June found that 52 percent of Americans support the Arizona law that went before the Supreme Court. Other polls have shown even higher levels of support.

To Gallegly, illegal immigration is an economic issue because undocumented workers take jobs that could go to legal immigrants or American citizens. “I’ve been pretty straightforward on this issue for a long time and have done very well in 13 cycles,” he said. “But that isn’t why I did it. People used to say: ‘Boy, this is politically incorrect.’ But not everything that is intellectually honest is always politically correct.”