The problem goes much deeper than the simplistic answer.
How did the media, entertainment, public school education, universities, etc. all acquire a leftward bent.
Liberals work a lot harder than conservatives at integrating their thought into these social institutions.
We will never have much effect on government until we gain more control in these issues.
We need to stop investing in the Republican party and start working on grass roots organizations.
The media, entertainment industry etc. have been trained in John Dewey's incubator of socialism. It's not just the content either, it is also the method, the objectives, the unions and the fact of government schools existence. It may not be the only problem, and undoubtedly there are other contributers, but government schools account for around 85%-95% of the problem. It is simple to acknowledge the education establishment for liberalizing of America, but hardly simplistic.
I believe that it is the combination of two things. One, that leftists are patient. Not saying that they are more patient than rational people, but their patience is key. Two, leftists have very skillfully made their agenda into a ratchet. That is, they understand that is self defeating to try to get every leftist policy/program they want implemented all at once. Instead they focus on securing small victories, “ratcheting” them in place as the widely accepted societal standard, then working towards their next small victory. If they fail it’s no big deal because their ratchet has guaranteed that even when they lose, they win.
This is something that conservatives can learn from. Leftist’s ideals and visions may be driven by emotions and feelings, but the manner in how they work to achieve their goals is very rational. Conservatives on the other hand have ideals and visions driven by rational thought, but the manner in how we work to achieve our goals is very irrational and emotion driven.
The conservative, for the most part, is very absolutist and will disregard out of hand any policy or politician who does not fit the mold of conservative one hundred percent (I am only speaking generally). The leftist will champion any person or policy that will in some way advance his agenda even if it does not fit the leftist mold one hundred percent. As a result, leftists are constantly making gains, or at the very least in a position to fight for gains, while conservatives are almost always playing defense. A perfect example of this is the gay marriage issue. Ten years ago would it have been considered a conservative ‘victory’ that a judge stated that a ban voted on by the citizens of a state didn’t violate the state constitution? Even when they lose, they win.