There is no "liberal". There are only excuses for control on issues on which that particular mindset finds appealing. An example of this would be the notion of the social-welfare state.
There is no "conservative". There are only excuses for control on issues on which that particular mindset finds appealing. An example of this would be the notion of expanded police powers, or police type state.
In the end, those people are "played" against one another for the furtherment of OUR goals. Not theirs. The result in these examples? Control on the social side through a welfare type society ENFORCED through expanded police powers. Exactly what we wanted and planned for. Concentration of power in the state at all costs. As one side is given power, they are given a goal to accomplish. When the "people" "elect" another side, they have a different task to complete. THAT is why it does not matter who you vote for IN THE LONG RUN.
In the short run, it does matter as each side has a different goal for their "turn". It is designed in such a way that each side must go as far as they can to modify the system for their required goals for our purposes. To push and push until the electorate cannot stand any more pushing. Then, on to the other "side" which does the exact same thing (with different goals) until the switch repeats itself. All at the request and demand of the electorate. They are getting exactly what they want. That is why it works. That is also why the communist and facist models of power attainment, having been tried as shortcuts, do not work and never will.
Thus is the grand design of the system. Simple, yet effective. A communist style social state, with capitalist controls, with the security apparatus of the fascist. This is the final, necessary, and most efficient system.