Prediction: Illegal immigration, an issue that has slipped from the headlines, is about to get more visible again.

Surprisingly, it’s not because conservative Republicans are raising Cain. No, liberals might be the catalyst that revives this topic, restoring its importance in the American political debate.

Because angry conservatives and their red-faced attacks on illegal immigrants have dominated the news since 2006, it’s easy to forget that the first organized warnings against massive illegal and legal immigration came from the left. In particular, green groups oppose the population growth that immigration brings, contributing to sprawl and traffic congestion. A growing immigrant population also depletes natural resources, the greenies say, using water that we’ll need someday, particularly in view of apocalyptic predictions of drought stemming from global warming.

Organized labor, too, has always harbored back-channel angst about illegals. While the unions may see some immigrant laborers as their membership base in the future, in the short run they worry that immigrant workers could displace union workers and disrupt labor markets.

Lately, it’s big-government liberals who might be worried about the secondary consequences of illegal immigration. As the economy weakens, illegal workers and their families are some of the first victims, forcing many into the social-services safety net. Who pays for these services? State governments on ever-tighter budgets are being handed the bill. And when illegal immigrants turn to crime because they can no longer support themselves through traditional means, where do they go? State and local correctional facilities are asked to house more costly inmates.

Given this background, it’s not surprising that FAIR, the Federation for American Immigration Reform, an immigration opponent, released a poll in Senate Majority Leader Harry Reid’s (D) Nevada recently. The survey found strong support for a FAIR report’s notion that illegal immigration is wrecking the state’s finances. FAIR’s report claims that illegal immigration costs the state $630 million annually. The poll found that almost 77 percent of Nevadans feel illegal immigration hurts their state’s budget.

FAIR’s report deftly plays to the right, reporting that the state is spending $515 million a year to educate the children of illegal aliens, $85 million a year on unreimbursed healthcare for illegal aliens and $31 million a year to incarcerate criminal illegal aliens. But those same numbers can be spun to create stronger opposition among liberals. School and healthcare bureaucracies are prized pinnacles of liberalism, so if illegal immigration threatens those institutions, something must be done.

Further evidence of the coming Democrat initiative on illegals is the rhetoric of incoming Homeland Security Secretary Janet Napolitano. Bolstered by data from a Greenburg Quinlan Posner poll taken in 2008, Napolitano is harping on the “rule of law,â€