They're sucking up to immigrant voters at home.
Wife, that's not worthy of you. "Sucking up for votes" is just one more slightly sleazy, political tradition, and unlike the subject at hand, it doesn't affect the end of civilization as we know it.
Besides, I want immigrants to become hard-working, tax paying contributors to the American way of life. Thanks to Al Gore's Reinventing Government INS scheme, we've got a lot of work to do to re-capture the immigrant vote. I don't mind conservatives trying to do just that.