You got voted down, but your sentiment is reasonable. Times are pretty rough right now, politicians seem worse than ever, and people seem to be more ready to hate each other than ever. But the trajectory is controlled by individuals.

Heinlein wrote this in a dark period in history too. The writing of it was resistance against the trajectory of his times. Belief is a choice. Action is a choice. If you don't feel optimism, that's OK to recognize. But then make a choice: to believe something good about your neighbor, to honor something noble about someone you disagree with, and to act as if we each can do better than societal trends seem to indicate.