As always, an attempt to foresee the future can be aided by looking to the past. The difficulty in recognizing a conceptual shift occurring is that as individuals we exist within its context. It is difficult to perceive the movement of the continents, but we can clearly see its results when we look at the history of geography. Similarly, a history of the evolution of liberty in America suggests changes that were incremental, but nonetheless profound, in their culmination. That history is of a regime founded in a negative liberty tradition which then shifted into the realm of positive liberty.
Negative liberty refers to freedom of the individual from some outside authority.
Conversely, positive liberty refers to freedom of the individual to something previously prohibited. Like continents as part of Pangea, these concepts of liberty began as one, but are now worlds apart. Rooted in the thought of John Locke and other classic liberal political theorists, it shunned the oppressive power of the state. The individual was allied with the private, commercial sector against the government. Historical context for this period is key in that the American revolution was obviously a break from heavy-handed rule of the British crown.