Young undocumented immigrants who are allowed to work legally in the United States should be allowed to drive legally, too. It makes perfect sense, if only for public-safety reasons: people need to drive to work, and they should follow the law and be demonstrably competent, registered and insured.

But with the politics of immigration, nothing is ever that simple.

The issue of driver's licenses for the undocumented became urgent when the Obama administration decided last summer to defer deportations and grant work authorization for certain immigrants who were brought here illegally as children but had clean records and met other qualifications.

The program, called Deferred Action for Childhood Arrivals, was designed for young people who would have been legalized under the Dream Act, a worthwhile bill that has long been blocked in Congress. The administration's aim was to allow so-called "Dreamers" to get on with their lives.

But doing so often requires a driver's license, and the states, not the federal government, decide who gets those. In Arizona, where government hostility to the undocumented runs hot, Gov. Jan Brewer swiftly issued an executive order denying licenses to recipients of deferred action.

It was a spiteful act of discrimination, since the work-authorization papers those immigrants receive — not to mention their Social Security numbers, which they can also get under the program — would ordinarily have been enough to meet the ID requirements of Arizona's motor-vehicle laws. Nebraska and Michigan similarly deny licenses to these young immigrants.

Many other states, however, have reached the obvious conclusion and announced that recipients of deferred action would be allowed to seek driver's licenses, too. The issue is moot in New Mexico and Washington, which already grant licenses to all qualified drivers regardless of immigration status; Utah issues driver permits to people who cannot prove they are here legally.

Those states have taken the broader, wiser course — extending responsibility and accountability over a shadow population. The Illinois Legislature is considering a bill to allow the undocumented to receive temporary driver's licenses, a move that Mayor Rahm Emanuel of Chicago has endorsed.

Driver's licenses for the undocumented has been a radioactive issue politically. Here's hoping that the administration's program calms things down, and that more states see the wisdom of making the roads as safe and regulated as possible.