You can't honestly agree with any of the major parties though, if a good percentage of the country actually voted for radical parties then the major parties would have to take note of this and adjust their policies accordingly and then maybe you would find that one of them would create an all encompassing set of policies. Which would be nice.
As much as I may disagree with the major parties, I disagree with the irrational fringe parties much more, so why would I vote for them?
This is a serious question, you appear to be advocating that because I disagree with position A, I should vote for position B which I disagree with more than I disagree with position A, just to send a message to those who advocate A?
That would just result in more politicians moving towards B, it would be a total own goal...