Couple of things from me.
Yes they are pretty boring, but just in case have an exit strategy.
Take a scanner out of your unit find and earpice, and use it. If the cops are going to move, you'll have a few moments notice.
Talk to officials before hand, and find out where they will be coming from if their are problems.
I just shot a little bit as incognito as I could (between cars, from behind trees, and from behind my reporter), I didn't want to give them a reason to be out there longer. After I got my shots, I put the camera on the ground, ready to shoot yes, but not being obvious about being with the news.
At the last rally, they were scheduled to go 2 hours, but lasted only 22 minutes. There were more protesters there than Klan members.
Have fun!