Granted, the Confederate flag's true meaning (an army's battle flag) has been hijacked by the winners (the Northern Army of Aggression.)
Keeping that in mind, and the fact that historians (not all, but most) insist on called the Northern War of Aggression a "Civil War," it's not hard to see what the fuss is all about.
A "Civil War" is actually a war started by a division of a nation intent on taking control of the "Central Federal Government."
A war of "Secession" is a war in which a group of people (Southern States in this case) chose to leave the Union and start their own country. Lincoln clearly was a murderer in this instance when he caused the death of thousands of Confederate and Union soldiers in this successful attempt to maintain power.
The so-called "Civil War" was not about slavery (which is despicable in any form) and slavery was abolished by Lincoln anyway, Congress did so a couple of years after the "Civil War."
So, Huckabee didn't do anything wrong, except be a wacko religious freak.