The scariest voice for Social Conservatism, because he has a natural charm. I think he would've done better than McCain due to economic populism, though I also think the Republican brand was too badly damaged in 08 for any Pubbie to win.
You are definitely right about Mike Huckabee and how he would have done in 2008. I feel he would have carried all the McCain states and would have picked up North Carolina, Indiana, Ohio, Iowa and maybe Florida and Virginia. In addition, I think Huckabee's faux economic populist message might have improved his performance among white working class voters. Either way, Mike Huckabee as President is actually a pretty scary thought considering his views.