AMERICA’S HALF-BAKED immigration system is riddled with unfair, arbitrary and inhumane provisions, but few are so senseless and cruel as those covering the undocumented immigrant spouses and children of U.S. citizens. Now the Obama administration is proposing a prudent rule change that would prevent thousands of pointless family separations and prompt untold numbers of illegal immigrants to seek legal status through lawful channels.

Currently, undocumented spouses and children of American citizens are eligible for green cards if they return to their native countries to apply for U.S. visas. But when they do, they are automatically barred from reentering the United States for up to 10 years — the penalty for having been unlawfully present here.

The way around those harsh measures is to prove that family separation would cause a U.S. citizen “extreme hardship” — for instance, by depriving him of the family income or help with child care that the immigrant spouse provided. The catch is that while U.S. immigration authorities grant thousands of such waivers annually, the process takes six months on average, and sometimes much longer, stranding spouses and children far from their families. Given the long delays and possibility of rejection — and prolonged family separations — many never bother to apply.

In practice, most of those who apply for waivers are Mexicans, and the vast majority of them are successful. Of some 17,000 waiver applications filed with the U.S. Consulate in Ciudad Juarez, which handles the paperwork in Mexico, about 90 percent were approved.

The rule change, proposed by the U.S. Bureau of Citizenship and Immigration Services, would allow such spouses and children to remain in this country while they seek provisional waivers. Nothing else would change: Once a waiver is granted, the immigrant would still be required to return to his home country to apply for a visa. But the shift would streamline the process and cut family separations to the days or weeks it takes to issue a visa, rather than the months required for a waiver application.

It’s possible that opponents of illegal immigration will cry “amnesty” — they rarely miss an opportunity — but the proposal is little more than a tweak. After all, it would favor people who are already members of American families and are overwhelmingly eligible to receive green cards anyway. Why tear them from their jobs, homes, spouses and parents for months on end? Nor is it likely to encourage phony marriages, since immigration and visa authorities would apply the same scrutiny to such arrangements as they do now.

Officials hope that the proposal — a change in administrative law that does not require congressional approval — will go into effect after a comment period by the end of this year. If it does, it could help tens or hundreds of thousands of immigrants and their American families to lead normal lives, free of the burdens imposed by a dysfunctional immigration system.