This new campaign video attacking Rick Perry on education benefits for undocumented immigrants represents the return of the bad old Romney.

No one imagines Romney to be an authentic, Tom Tancredo-like, anti-immigration politician. He defended George W. Bush’s 2005 comprehensive immigration reform against conservative charges of “amnesty.” He once said, “I don’t believe in rounding up 11 million people and forcing them at gunpoint from our country,” which qualifies him as an immigration moderate in some Republican circles.

But Romney has consistently used immigration as a wedge issue in Republican primaries. In August 2007, he went after Rudy Giuliani in a New Hampshire radio ad for tolerating “sanctuary policies.” In December 2007 he attacked Mike Huckabee in Iowa for supporting “taxpayer-funded college scholarships for illegal aliens.” After first calling John McCain’s immigration reforms “reasonable,” he attacked them as “amnesty.”

Clearly, Romney strategists saw an opportunity in Rick Perry’s statement that Republicans were being heartless on education benefits.  But exploiting this political opening has significant costs. Four years ago, immigration was exhibit one in the case for Romney’s political inauthenticity. Now his campaign has revived those memories. The specific argument that Romney presses is weak. Of all the measures against illegal immigration that might be contemplated, the punishment of children who have committed no crime can’t be high on the list.

But perhaps most disturbing is the tone of the Romney ad itself. It is not simply an issue-oriented contrast. It uses a statement praising Perry by former Mexican President Vincente Fox as though it were an endorsement by Iran’s President Mahmoud Ahmadinejad. The last time I checked, Mexico was an important ally – a country that Romney, if elected president, would need to deal with daily. Fox’s words in the commercial are innocuous – simply thanking Texas and Perry for the education measure they had passed. So why is Fox’s statement supposed to be disturbing or sinister? Because Fox is a foreigner? Because he has a Mexican accent?

This is really an ad one would expect of Tancredo, not Romney. Mitt Romney is better than this. He just needs to act like it.