From one of my favorite websites, a question pertinent to this week's topic. Do individuals "ever really have [influence] over the evolution of politics in a country, a region, or even the whole global political systems?"
The question is asked as a result of the recent deaths of Vaclav Havel as well as Kim Jong-Il. The former was president over a democratic republic (albeit a recently created one) while the latter ruled a totalitarian autocracy. The story ponders the influence of individuals in each system and points out what this contrast tells us about what well designed institutions do for a republic - they make it stable.
The arbitrary nature of rule in North Korea makes it far more prone to instability (I suppose by definition) while rule by duly established institutions have procedures within them to ensure that decisions will be more or less stable. They can be subject to change, but not rapid, destabilizing change.
This is a central point I try to make clear in the course material. Well constructed institutions placed in a proper relationship with each other (a relationship that has worked itself out over time) are central not only to the preservation of liberty, but to the establishment of a stable society that leads to prosperity.