John McCain seems to be doing his best to build his own version of a double-layer border fence between his campaign and the hardcore anti-immigration wing of the Republican Party.

In a new ad up Friday in Colorado, New Mexico and Nevada, McCain plays a clip from a GOP primary debate last June, in which he vehemently defended the immigration reform legislation that nearly brought his campaign down. The ad -- and McCain's comments -- points out the Hispanic names on the Vietnam Veterans Memorial and the Latino immigrants serving in Iraq and Afghanistan now. "Let's from time to time remember that these are God's children," he says. "They must come into our country legally, but they have enriched our culture and our nation in every generation."

The ad serves two purposes -- one, like nearly all McCain ads, it evokes the sense of honor he finds in military service (possibly reminding voters of his own), and two, it brings voters back to the John McCain who fought hard for an immigration bill his own party fought even harder against. Of course, that's mostly important because in the year or so since the bill crashed and burned in the Senate, McCain has spent a lot of time trying to flee from his own legislation, telling Republican primary voters the border needs to be secured before any undocumented immigrants get legal status. Earlier this year, he said he wouldn't vote for the bill if it came up again.

Possibly because of that, Barack Obama beat McCain 47-22 in a recent AP-Yahoo News poll of Latino voters. The new ad -- which features a shot of nativist Rep. Tom Tancredo, who ran for the GOP nomination on a border security platform, looking angry at McCain -- might help close the gap. McCain's campaign also says Obama is in no position to lecture him on immigration; while Obama participated in the bipartisan talks last year that crafted the bill, he later pushed for an amendment supported by unions that would have helped kill the legislation if it had passed.

But you'll notice the ad is in English -- which means it's not just aimed at immigrants, but also at moderates and independents who liked McCain's maverick image the last time he ran. Besides the immigration message, the ad has another layer: "See, this guy stands up to his party! He's not like all those other Republicans!" And that may be the message McCain wants to drive most of all.