It's not about whether or not someone is a bigot, but whether or not the argument which that someone is arguing is worth being a bigot about.
Ideas, of course, have a place in fiction, and any writer of fiction needs a mind. But ideas are not the best subject matter for fiction. They do not dramatize well. They are, rather, a by-product, something the reader himself is led to formulate after watching the story unfold. The ideas, the generalizations, ought to be implicit in the selection and arrangement of the people and places and actions. They ought to haunt a piece of fiction as a ghost flits past an attic window after dark.