Writing for Commentary‘s “Contentions” blog, Jonathan S Tobin examines the possible impact on the presidential race of Monday’s U.S. Supreme Court ruling in the controversial Arizona immigration case.

Some liberals are declaring the Court ruling a victory because much of it was tossed out. But for most of those who cared about this issue, the “check your papers” measure was the key to the controversy, and its survival must be considered a limited victory for Arizona. It is possible, as liberals are hoping, that even that point will be eventually ruled unconstitutional if it can be proved that it is enforced on a racial or ethnic basis. But it’s worth remembering that the Solicitor General who argued the administration’s case for throwing out the entire law flopped because even liberal justices agreed that his position was, as Chief Justice Roberts pointed out, “that the federal government just doesn’t want to know who is here illegally or not.”

As much as his tougher line on illegals is one that will cost Mitt Romney Hispanic votes in November, taking a position that the government should not enforce existing immigration laws and offering amnesty to large numbers of undocumented aliens will hurt the president with the rest of the country. As David Paul Kuhn pointed out in an insightful analysis on RealClearPolitics.com, the president’s growing problem with voters who are neither African-American nor Hispanic is a far greater obstacle to victory than Romney’s problems with Hispanics. Though non-whites are an increasingly larger percentage of the electorate, as Kuhn writes, Obama is currently getting a smaller share of the white vote than any Democrat since Walter Mondale and far less than the 43 percent he got in 2008.