Mitt Romney once promised that on “day one” of his presidency, he’d drop the federal lawsuit seeking to overturn Arizona’s go-it-alone immigration law.

On Monday, the U.S. Supreme Court pre-empted that pledge, striking down most of that law just as Romney prepared to attend a GOP fundraiser in Scottsdale, Ariz.

The timing was awkward, but the truth is that Romney would rather not talk about immigration now, period.

During the Republican primary debates, Romney positioned himself to the right of his rivals. He endorsed the attrition-through-enforcement strategy behind Arizona’s law, which essentially seeks to make life so difficult for undocumented immigrants that they will “self-deport.”

Romney also said he’d veto the Dream Act, a proposed law that would provide a path to citizenship for the children of undocumented immigrants if they went to college or served in the military.

With the nomination in hand, Romney has largely steered clear of the immigration debate, aware of the growing political clout of Latino voters — who as of Monday favored President Barack Obama over Romney, 66 percent to 25 percent, according to a Gallup poll.

Romney would rather campaign on the economy, the topic of greatest concern to voters, including Hispanics.

The Obama campaign, however, has taken pains to remind voters that Romney “paraded around the country with the nation’s leading anti-immigration voices” — including Arizona Gov. Jan Brewer, who signed SB 1070 into law, and Kansas Secretary of State Kris Kobach, who largely wrote it.

Last week, Obama scored big points with Latinos by announcing an administrative order that allows young undocumented immigrants to stay and apply for renewable two-year work permits if they finish school or join the military. It doesn’t provide a path to citizenship — only Congress can do that — but it was as close as the president could come to enacting the Dream Act without help from Republicans.

Romney’s mumbled response to that action illustrated the corner he’d painted himself into: He called Obama’s plan a short-term fix but didn’t spell out a long-term solution of his own.

His earlier suggestion that states might handle immigration matters themselves was all but torpedoed by the Supreme Court. Half a dozen states had enacted laws patterned after Arizona’s, but the court said setting and enforcing immigration policy is the job of the federal government.

The justices said Arizona could require its police officers to question and briefly detain anyone they suspect of being in the country illegally. But it can’t hold suspects on immigration charges without federal approval, and it can’t make it a state crime for immigrants to seek work or to fail to carry documentation.

Even before the ruling, some states were having second thoughts about those laws. The Arizona approach might drive out illegal immigrants, but it also scares away tourists and businesses.

Thousands of immigrants have, in fact, self-deported, largely because of a lack of jobs. Many will be back when the economy picks up, however, and many American employers will welcome them, just as they did before. That underscores the biggest failure of our immigration system: It doesn’t provide enough legal workers to meet the needs of employers.

Editorial by the Chicago Tribune