My first instinct is that these "Obama supporters" are white (since there are hardly any minorities in that part of New Jersey).
I'd also mention that this story has a ring of truth to it. For those of you who don't know Warren County or the layout of New Jersey, it's not all that unusual to find Confederate flags hanging in front of homes there. In fact, the rural character and hilly terrain there are such that if someone were blindfolded and brought there, they might swear they were in western Virginia, Tennessee, North Carolina, etc.
I live in Tennessee, not far from either the birthplace of Nathan Bedford Forrest AND the birthplace of the KKK.
Here, you may see a few Confederate Battle Flags, but never a Confederate Bonnie Blue Flag, the official flag of the Confederacy. You will see an American Flag flying on my front porch. In photos I have seen of early KKK rallies, there were NO flags of any description.
Also, Forrest quit the KKK whenever he saw what it was being turned into.