The argument I have heard from “open-minded” individuals is that the use of the confederate flag, or an appreciation / loyalty to the Confederacy is not so much about slavery as it is about state’s rights.

I hereby proclaim this bullcrap.

http://en.wikipedia.org/wiki/Cornerstone_Speech
The Cornerstone Speech is so named because of one section.
In particular,

“
The new constitution has put at rest, forever, all the agitating questions relating to our peculiar institution — African slavery as it exists amongst us — the proper status of the negro in our form of civilization. This was the immediate cause of the late rupture and present revolution. Jefferson in his forecast, had anticipated this, as the “rock upon which the old Union would split.” He was right. What was conjecture with him, is now a realized fact. But whether he fully comprehended the great truth upon which that rock stood and stands, may be doubted.
…
(Jefferson’s) ideas, however, were fundamentally wrong. They rested upon the assumption of the equality of races. This was an error. … Our new government is founded upon exactly the opposite idea; its foundations are laid, its corner–stone rests, upon the great truth that the negro is not equal to the white man; that slavery — subordination to the superior race — is his natural and normal condition.
“

I’m afraid this leaves no room for discussion. The confederacy wasn’t about state’s right; it was about slavery. The confederacy was formed because Republicans – the anti-slavery party – had gained power, and the south didn’t want to lose their cheap labor.

Rationalizing the use of the confederate flag, and glorifying the confederacy is much like doing the same for the swastika, and the nazi party.
Indeed both movements were based on the belief that one race is somehow superior to another.

The difference:
Germany has the common decency to be ashamed of what it did.
The Southern U.S. still doesn’t see what it did wrong.