The McCain camp told all their people to vote Huckabee so Romney doesn’t get them.
Huckabee’s does his job of being in the race to steal delegates for McCain.
McCain can’t win the honest way and he knows it; hence another dishonest guy colludes with him, selling his soul cheap.
Then McCain is even more an idiot. In exit polling so far, the majority of Huckabee voters list McCain as their second choice. If Huckabee were not there today, McCain wins states that Romney might eek out.