I am not big on conspiracy theories. My best guess is Huckabee is angling for a big book deal. He is after publicity.
I’m sure that’s a side benefit, but that is what I believe about candidates like Huckabee or Santorum. They know they cannot win, but they stay in the race just long enough to ensure real alternatives cannot win and then they pull out.
Every Presidential election.
But while running for his own reasons, the effect of his campaign is to be a conservative spoiler who helps the GOPe.