It's their job, some of them actually get paid as in the re-count protests from the 2000 selection. A good number of those were bussed in to Austin, and given signs the campaign printed and distributed. As to harassing, I always think they are rude and aggressive lot myself. The DPS (Capitol security force here in Austin, TX) does a good job at creating a buffer between the groups, but there is always hate talk and the like.
There have been reported incidents of people having their cars vandalized, if they have a lot of left leaning or peace bumper stickers on their cars. And that's in Austin mind you, the liberal capitol of Texas. You can imagine what kind of reaction you would get in the rural areas, lets just use Crawford for an example. They're boycotting girl scout cookies there remember? Can't get any more back asswards than the rural areas of Texas.
I expect that the rally on march 20th in Crawford will see a lot of freeper and TX young and stupid repukes come out of the woodworks to counter that.
http://www.marchcrawford.org/Sonia