Are mistrust and distrust synonyms?
And if so, how have two such similar words coexist for so long? Google N-grams suggests the two words have coexisted since the 1700's.
The Grammarist has a discussion on these words:
That sums up my thoughts pretty well. I like the distinction, but often people don't recognize it.
I think distrust has evolved to become the active-voice form of mistrust.
Consider the following sentences:
I distrust our gardener. -vs- I mistrust our gardener.
Hate and mistrust are the children of blindness. -vs- Hate and distrust are the children of blindness. --again, the first form sounds more correct in the current era.