This is the only song with no words. The instrumental makes me think of birth, but then the question is, "What's next?" Political parties fight over abortion and welfare, and much more.
All of Mockingbird is about this question of what do we do with life. We must fight for life and stand against senseless abortions, but we must still care about that life after it's been born. Education, medical care, oppurtunity, family, etc must all be addressed in a consistent ethic of the kingdom.