The administration’s lawsuit against the State of Arizona for attempting to stem the tide of illegal immigrants across its southern border isn’t just an exercise in litigation. It’s an exercise in irony.

For once upon a sad time, namely the bad old days in these Southern latitudes, states systematically denied a large class of their citizens the equal protection of the laws, denying their rights and, when challenged, waving the banner of States’ Rights to cover the mistreatment of their own citizens.

The federal government was bound by law and conscience to step into that vacuum of law, and protect the privileges and immunities of all its citizens, to use the language of the Fourteenth Amendment. And it finally did so. The happy result is that the evils of racial segregation enforced by state law, and defended by various and distinguished advocates, is now a thing of the past.

Now the legal positions are reversed. It is the federal government that has long neglected its duty to secure the country’s border, and so protect its citizens – especially in states like Arizona. So state governments are trying to fill that vacuum. And it is the federal government, waving the Supremacy Clause of the Constitution, that seeks to divert attention from its own failure to enforce the laws of the United States.

For connoisseurs of irony, a sage observer once noted, politics is a virtual banquet

Of course, the U.S. Department of Justice is suing the supposedly sovereign State of Arizona. It’s so much easier to file suit than to secure the country’s border.

The flood of intruders crossing that broken border represents a danger to the life, liberty and property of Arizona’s citizens – especially when the trade in illegal drugs runs through the Grand Canyon state. That geological wonder isn’t the only prominent hole in Arizona; its porous border with Mexico is another.

Nor is Arizona the only state struggling with illegal immigration, which has become a national phenomenon. It’s just more intense in places like Arizona, California and Texas. But because it’s a national issue, does that mean illegal immigration can only be tackled by the national government – and states need to butt out?

At this point, the thought might occur to a simple layman unlearned in the law that, just because something is a federal problem, like anything from illegal drugs to kidnapping, doesn’t mean it’s only a federal problem. States have passed a multitude of their own laws against various crimes. Why not illegal entry?

Does being in this country illegally mean you can’t be in any of its states illegally? You’d probably have to be a licensed lawhead to defend a position like that – it defies common sense – but there’s no shortage of lawyers in Washington.

Of all the many crimes that are both federal and state in this system of dual sovereignty, why has the administration chosen to make this one an exclusively federal preserve? Can it be because the other crimes don’t have so great a body of voters who’d like to ignore it?

With this Supreme Court’s command of the law, or lack thereof, the feds stand a good chance of prevailing when trial comes to appeal. Because of the intricacies of constitutional law, the border between state and federal jurisdiction when it comes to immigration law may be as vague as Arizona’s own border. And the feds may manage to assert an exclusive jurisdiction over it – when they’re not asking state and local authorities for help.

At the moment the administration is bringing its full arsenal of doublespeak to bear against the state – and people – of Arizona. For example, the feds’ brief asserts: “In our constitutional system, the federal government has pre-eminent authority to regulate immigration matters.”

But can anyone seriously maintain that the federal government has exercised that authority along the no-man’s land that is much of the country’s southern border? Instead, it has let a vacuum of law and order develop there, and the results have been all too predictable. Is it any wonder Arizona has sought to fill that vacuum?

What the feds are really saying is that Washington has pre-eminent authority not to regulate immigration matters. Or can anyone with eyes to see believe immigration along the border is now well regulated?

It’s interesting, and revealing, that not even the Department of Justice bases its case against Arizona’s new law on the claim that it’s just a legalized form of racial profiling. That’s been the biggest complaint of those who can’t have read the state law in question, or have chosen to ignore it.

The law actually bars profiling: “A law enforcement official or agency of this state or a county, city, town or other political subdivision of this state may not consider race, color or national origin….”

No wonder the feds have chosen to make this a case of federal vs. state jurisdiction rather than one involving ethnic discrimination. Because there is no evidence that it does. Instead, Arizona’s sin is that it is trying to enforce the law. Which is more than the federal government has been able to do.

© 2010 TRIBUNE MEDIA SERVICES, INC.