I think boosting morale is a good enough reason. I'm not a fan of yard signs, though, as they clutter a neighborhood. I think a presence on the internet--refuting left-wing garbage, participating in online polls, etc.--probably has more of an effect.
I don't know how to post a link, but here's one to a pretty good t-shirt I may order for DH.
http://www.zazzle.com/tell_them_im_coming_shirt-235353548740360033