Scientific American's departing editor and the politicization of science

"In the process, SciAm played a small but important role in the self-immolation of scientific authority—a terrible event whose fallout we'll be living with for a long time."

Which is it - small or important? All that seems like a bit much.

For want of a nail the shoe was lost. For want of a shoe the horse was lost. For want of a horse the rider was lost. For want of a rider the message was lost. For want of a message the battle was lost. For want of a battle the kingdom was lost.

Was the nail small or important?

Why does a person want a nail and then lose a shoe? Why does a person want a shoe and then lose a horse? Why does a person want a message but lose the rider? Why does a person want a message and lose the battle? Why does a person want a battle but lose the kingdom?

I don’t understand the point or reference being made.