Here’s a question people are going to be asking if the current polling holds up: Illegal immigration appears to have saved Jan Brewer in Arizona. Why hasn’t it sunk John McCain? According to Rasmussen, McCain is up 20 points over J.D. Hayworth with less than a month to go before the primary. Hayworth has campaigned heavily against McCain’s longstanding support for amnesty and predicted the senator will return to semi-open-borders form if reelected.

Part of this undoubtedly has to do with Hayworth’s own problems with conservatives as well as McCain’s reinvention as an immigration hawk. But Hayworth’s conservative credentials are at least arguably stronger than Brewer’s before she became a stout defender of Arizona on illegal immigration. And if Tom Tancredo decided to pull a Lou Dobbs while running for governor of Colorado, would anyone take his conversion seriously?