'The light at the end of the tunnel' was an analogy (is that what it is?) used a lot in the Vietnam War. When there really was no light, just tunnel.
The thing is, sometimes there IS a light at the end of the tunnel. I believe that's true today. But seeing a light doesn't tell you how far away it is, and how long it will take to get there. And it seems a little farther away now than it did 4 years ago.
I may get there with you, MLK said, but I want you to know tonight, that we, as a people, will get to the Promised Land.