Hmmm... Libel and slander laws are specifically inapplicable to political speech. Trademark laws are not.
Yes, I can understand the G.O.P. wanting to avoid some of the ridicule they've earned. And trademark laws can do this for them. And there's a point there. Why should they go to the trouble to design a logo just to be abused with it?
But the free speech notion keeps coming back to my mind. I thought the primary purpose of the parties was to provide an organization to groom and provide those citizens who are capable of governance. I didn't know that licensing revenues were more important. This seems to indicate that the real purpose of the G.O.P. is to make not governance, but money.
I don't think they need to be prevented from protecting their trademark. I just think they're damned fools to do it.