A tendency to favour Smollett? (4)

I believe the answer is:

bias

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'a tendency' is the definition.
(bias is a kind of tendency)

I don't understand how the rest of the clue works.

(Other definitions for bias that I've seen before include "Unfairly influence" , "One-sided inclination" , "colour" , "One-sided prejudice" , "Large city in Florida" .)

I've seen this clue in the Evening Standard.

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