He epitomizes "compassionate conservatism," and thus at least stands more of a chance with hispanics than anyone else. As far as upper/middle income suburbanites go, their voting values are more shallow than you think. As soon as prosperity returns we'll see their traditional myopia set in, with a full return to commercialism and isolationism (and thus the GOP).
After W, "compassionate conservatism" will never sell. To anyone. And suburbanites vote on 2 issues, national security and the economy. Right now the only economic selling point Huckabee may have is the Fair Tax, which no one knows enough about to feel comfortable with, let alone vote for.