A person who rules without consulting the opinion of others

One word substitute is Autocrat.

Democrat: an advocate or supporter of democracy.
Bureaucrat: an official in a government department, in particular one perceived as being concerned with procedural correctness at the expense of people's needs.
Autocrat: a ruler who has absolute power.
Fanatic: a person filled with excessive and single-minded zeal, especially for an extreme religious or political cause.