Huckabee doesn't control his delegates that way, moreover McCain himself doesn't control what his delegates do on the second ballot. Huckabee can tell them he wants them to vote for McCain, but they will do whatever they want. If this thing is still open going into the convention there will be lots of small deals made back and forth by phone and at the convention.
McCain was a distant third in that state's convention to choose national convention delegates. Romney had 41% but not obviously the magiuc majority. So, McCain ordered all his delegates to switch to Huckabee, and give the state to Huckabee. Most of them obeyed. McCain had only 11 delegates voting for him on the last round.
That's how that game is played, in conventions. Click below for more.
Congressman Billybob