The best way to popularize something is to ban it/make it illegal....
This is true. You're gonna see a whole lot of people who previously didn't care, digging the flags out.
From the NC link in the OP:
>> The state DMV said it has issued 2,064 Confederate flag plates to members of the North Carolina chapter of Sons of Confederate Veterans.
The organization calls the flag an important piece of history and their heritage. Paul Graham of the group's South Carolina chapter said the flag shouldn't be conflated with the Charleston church shooting and that removing the image from public places won't change people's actions.
"It will not change anything. What it will do is it will embarrass and shame people that have nothing to do with this event – nothing," Graham said. <<
I'm not a member of that group, don't have the license plate and have no interest in it. But he's right.
Not to mention -- these plates are already out there, on the road. What are they gonna do-- make them all send 'em back for new plates?