People don't believe or understand that a community can lose hope. You can have a whole community where hopelessness is the norm, where folks don't have faith that things will get better because history and circumstances have proven over 30, 40, or 50 years that things don't get better.

This quote means that when a community experiences problems or challenges that last over a long period of time, people begin to lose hope. They start to think that things will never improve and will just stay that way indefinitely. This feeling of hopelessness can become the norm in the community, where people don’t believe that anything can be done to make things better.