WASHINGTON

--The constitutional implications of the Supreme Court's health care ruling will be debated until Election Day and dissected beyond it. But it is the court's immigration decision--and Mitt Romney's positioning on the issue--that throws the brightest light on the current presidential race. And the glare is not kind to the challenger.

Some have faulted Romney for a muddled response to the ruling--a tactical criticism that is largely unfair. It is difficult to be clear about an ambiguous decision. (The constitutionality of Arizona's "papers, please" law seems to depend on the politeness with which police deliver the "please" part.)

Romney aides also note that their candidate is uncomfortable with the whole enterprise of a president, or prospective president, cheering or jeering the actions of the Supreme Court in the manner of a pennant race. An admirable reticence.

Romney's whole post-primary approach to immigration--recently summarized in his speech to the National Association of Latino Elected and Appointed Officials--has been careful and reasonable. He faults President Obama for election-year urgency on immigration policy after 3 years of passivity. He highlights the scandal of double-digit Hispanic unemployment. He calls for easier family unification for permanent residents, green cards for those earning advanced degrees, and a path to legal status in exchange for military service.

Considered individually, these messages and policies make sense. Taken together, they are a strategic failure. Romney is being careful and reasonable on immigration in the midst of a five-alarm political fire.

Latino support for Republicans has been dropping since conservatives blocked President George W. Bush's attempt at comprehensive immigration reform. Romney accelerated the descent by pledging to veto the DREAM Act as president. His polling among Hispanics now bumps along at about 25 percent--a level that seems inconsistent with winning Colorado, Nevada, or perhaps even Florida. It is an uphill political task merely to match John McCain's level of Latino enthusiasm. Attaining even this modest goal will require an outreach strategy bolder than "Keep Calm and Carry On."