Good question. By default, yes Erics view is as valid as my own, of course. I don't agree with his argument as I believe it to be a false equivalence, but his view is as valid.
As to whether someone who would be 'upset' if their daughter married someone because they had voted Tory, again, I have to concede that their view is equally valid. I profoundly disagree with them, feel sorry for them, think they are probably being unfair to their daughter and future son in law and all the rest of it, but I do believe that all opinions are equally valid within the confines of the law.