Immigration reform had receded as an issue in the past couple years, thanks largely to the sagging economy, which translates into fewer of the menial, entry-level jobs most often filled by those in this country illegally. Many illegal aliens had "self-deported" themselves back to their country of origin, and many of their countrymen had decided not to come at all, or to wait until the economy picks back up.

But the issue is back front-and-center, thanks to the state of Arizona and to President Obama, who is newly empowered by the passage of his health care makeover and also desirous of an issue to fire up the left wing of his party.

The Arizona legislature has passed, and Republican Gov. Jan Brewer has just signed, the most restrictive immigration law in the country.

It law requires state and local law enforcement to check the immigration status of anyone they have a "reasonable suspicion" of being in the country illegally. The law requires legal aliens to carry proof of their legal status at all times - something already required by federal law since the 1940s. Failure to do so in Arizona now is punishable by up to six months in jail and a fine of up to $2,500. Day laborers in the country illegally can also be arrested for soliciting work, under the new law. And Arizona law allows local police and governments to be sued if they fail to vigorously enforce the immigration laws.

Critics were quick to attack the law, calling it everything from "Hitlerian" to racist - a frequent tactic for those who are unable or unwilling to debate an issue on its merits. They contend it will be "open season" on Hispanics, with police indiscriminately targeting anyone with brown skin.

Not likely. Not only does the new law specify that race and ethnicity cannot be the sole factors in determining police enforcement, it specifies that officers must have a "legitimate reason" for stopping the person, even before any inquiring about immigration status. That is, the person must appear to be in violation of some other law before he can be questioned on this one.

Arizona does not have the most illegal immigrants - California has that honor, and other big states have considerably more - but the estimated 460,000 there now have a disproportionate, $1 billion annual impact in a relatively smaller state. And tightened enforcement elsewhere has pushed illegal border-crossers into Arizona. Gov. Brewer has a point when she says the state government was forced to act because the federal government hasn't. The so-called "virtual fence" approved during the Bush administration is more "virtual" than fence, unfortunately.

The state is not being dramatic when it claims to be "ground zero" for illegal immigration - much of which is growing increasingly violent.

The legal challenges to the law, when it goes fully into effect in three months, will not be long in coming, and Obama, who called the law "misguided," can be expected to throw the full force of the Department of Justice against it.

At this point, it looks like we can expect another full-bore battle on immigration between now and November. Unfortunately, that means that the debate, and any resulting legislation, is likely to hinge more on political opportunism than on hammering out changes to the system that would improve the guest worker program, for example, and on ways to finally take control of our Southern border once and for all.