By different means, going too far to any of the corners will lead to a collapse into totalitarianism.
To far in the libertarian direction gives you anarchy, which might be fun for a while, but soon someone will take advantage of the power vacuum, and take control of everything they can.
Examples can be found wherever existing leaderships dissolve, leaving chaos. Some parts of modern Africa, perhaps?
Too far in a conservative direction begins with legislating morality, until you get to the point where every part of one's life is governed by a strict moral code (or else!)
Examples are Islamic theocracies, and the Catholic church of the middle ages.
Too far in a liberal direction leads down a socialist road. In order to take advantage of the benefits of socialism, the economy must be controlled by the government. Representative governments can't make the decisions involved, though, because they represent disagreeing groups. So, authority gets delegated to various official bodies. This is inefficient though. Those delegated officials in charge of various sectors will clash, and be ignorant of what the others are doing, causing wasted resources and lost opportunities. To prevent this waste, control is consolidated under one administration... Which gives too much power to that body. Inevitably, that over-powered administrative body will come under the control of someone evil, who will then use the massive influence of complete economic control to seize control of the rest.
Examples: Nazi Germany, Soviet Russia.
That's why, unless you're a fan of authoritarianism, the only viable options are:
1- Moderate Libertarian
2- Moderate left
3- Moderate right
Am I right?