On this Election Day, the Latino vote may turn out to be the dog that didn’t bark.

Latino voters are thought to be among the most important swing groups in American politics. They are increasingly affluent, and last year a wave of stories appeared about how Latinos now outnumber African-Americans as the largest ethnic minority in the United States. Both major parties continue to make overtures to Hispanic Americans (search); both candidates spent the final Saturday before the election on the Spanish-language television show Sabado Gigante (search).

Both George W. Bush and John Kerry feature Spanish-language campaign sites prominently and run TV ads in Spanish.

But is it possible this critical swing vote is something of a mirage? According to some provocative new research on the most recent Census figures by William Frey, a visiting fellow at the Brookings Institution, the answer is yes. Frey claims that “the Latino swing vote is more apparent than real.”

“Fully one-third of Hispanics are below voting age, and another quarter are not citizens,” Frey writes in The Milken Institute Review (search), an influential quarterly journal published by The Milken Institute where Frey is a senior fellow in demography. “Thus for every 100 Hispanics, only 40 are eligible to vote, 23 are likely to register, and just 18 are likely to cast ballots. For blacks the comparable number is 37, and for whites, nearly 50.”

But as we all know, only a few battleground states (search) are still in play at this late stage, and so they will actually determine this election (and the campaigns have their lawyers crawling all over them for good measure). So will Hispanics make the difference there? Frey doesn’t think so. “Most large Hispanics concentrations are in states that are safely red (Texas) or blue (California, New York, New Jersey),” he says. “Arizona and Nevada may be close to the tipping point, but in both, the Hispanic population translates poorly into votes.” Hispanic voters could make a difference in Florida and New Mexico, he says.

While neither campaign would admit it, Frey’s findings illustrate why some issues have been played down this year, particularly immigration.

Polls indicate Americans typically hold somewhat conflicting views concerning immigration. Americans appreciate the contributions hard-working immigrants make to business and society – not surprising given the United States is an immigrant nation — but worry about too many illegal immigrants flouting American law and straining social safety net programs.

But Americans are more concerned about the border now, particularly given worries about terrorism. Public Agenda, a non-partisan opinion research firm, found that “half of Americans say the country is too open to immigrants and, since Sept. 11, there has been an increase in the number who want to reduce immigration. A recent Gallup survey found 58 percent wanted a reduction in immigration — a 20-point increase over the year before.” With terrorism still a front-burner issue, it would seem either candidate could score points by posing as tough on immigration.

Despite the heightened public interest in immigration (search) and border questions, the standard-bearers for the two major parties haven’t discussed immigration much, and neither has tried to make it a major issue in the campaign.

This is where Frey’s numbers come in. Given the relatively insignificant numbers of Latino voters (search), at least in this election cycle, the campaigns can afford to largely ignore Latino voters and any concerns they might have about presidential rhetoric that would appear anti-immigrant. At the same time, neither party wants to alienate what could be a potent political voting bloc in the future.

So while Americans might like to hear more talk about immigration – particularly tough talk in the context of border security — the candidates have felt fit to let this issue, save a few comments here and there, sit on the sidelines for this election.

The author is a former politics editor for FoxNews.com and is currently editor of TechCentralStation.com, a magazine focusing on science, technology, economics and public policy.