Taking a brief time out from a bruising partisan battle over raising the nation’s statutory debt limit this week, President Obama recently renewed his support for passing comprehensive immigration reform.

In a speech to the National Council of La Raza, the nation’s premier Latino advocacy group, Obama exhorted the group to create an external network that could circumvent Washington’s thick political climate.

Easier said than done. As the president himself is no doubt aware, granting legal recognition to an estimated 12 million illegal immigrants is a feat no president has been able to accomplish since Ronald Reagan occupied the Oval Office. It’s also something that Obama — with solid majorities in both houses of Congress during his first two years in Washington — has been unable to accomplish despite his most fervent wishes.

This unfulfilled promise has led to pointed criticism from Hispanic organizations that the president is insensitive to their agenda. Obama’s stalled immigration policy even led one prominent Congressman to get himself arrested in protest outside the White House.

To be fair, President Obama and Democrats want to legalize the millions of immigrants, mostly of Mexican extraction, huddled in the shadows of the economy — if for no reason other than the obvious electoral advantage such a move would confer. There are also convincing economic arguments in favor of legalizing millions whose economic activity supports family both here in the U.S. and their native country.

And images of undocumented immigrants being rounded up and deported make for distasteful prime-time news. But the political and empirical realities simply do not favor sweeping reform. There are legitimate reasons why Obama and Democratic leaders have dragged their feet, and few of them have anything to do with recalcitrant Republicans. The top reasons include the following:

Border-state violence along the Mexico-US border has skyrocketed. Northern Mexico has been riveted by drug-inspired terror that has killed scores of Mexicans and heaped intense pressure on the Obama administration to secure the porous border. The violence recently forced the Mexican government to deploy thousands of federal police to enforce the peace.

More recently, the Bureau of Alcohol, Tobacco and Firearms and Explosives has found itself at the center of a major controversy involving a controversial project called Operation Fast and Furious. The program has been faulted in the death of a federal agent, and embroiled the Justice Department in a growing political firestorm.

The eternal ‘black-brown’ divide threatens any legalization efforts. Black workers have little to fear from their Latino counterparts: Empirical data clearly illustrates immigrant workers have a negligible impact on the employment prospects of native workers. Still, stubbornly indelible perceptions exist that Hispanic immigrants — both legal and illegal — are stealing jobs from working-class blacks. With a fragile economy and black unemployment rate hovering above 16 percent, a push to legalize illegal immigrants would prove a hard sell to struggling workers. It could also throw a wrench in black/Hispanic relations.

Moral Hazard. Illegal immigrants are just that — people who did not enter the country lawfully. Giving them a path to citizenship creates a powerful incentive for others to circumvent well-established legal process for citizenship, and virtually guarantees another president will confront a similar problem 20 years hence. The contemptuous “amnesty” label used by many conservatives applies for a reason.

The political math doesn’t add up. While it is true that the GOP stymied Obama’s efforts to at least pass the controversial DREAM Act, it was actually five holdout Democrats whose reservations ultimately killed the bill. That Obama was unable to push through an immigration bill — even after expending political capital on his massive health care and stimulus initiatives — underscores how Democratic opinion on the topic is hardly uniform.

And whatever can be said about the GOP, in this case they can hardly be faulted for inconsistency or political hypocrisy — an outcry amongst the conservative grassroots helped doom President George W. Bush’s own immigration effort in his second term.

In truth, Latinos are hardly the only ones frustrated with President Obama these days — virtually everyone is. Stalled immigration reform — like several other high-profile Obama campaign promises such as the closing of Guantanamo Bay, the winding down of the Afghanistan and Iraq conflicts (not to mention the start of the Libya bombing campaign) — has become a proxy for frustrated political ambitions.

Candidate Obama made a number of pledges he is finding it difficult to keep. As 2012 draws nearer, the president is likely to discover that lofty speeches are easier to deliver than tangible results