The commissioner may be removed from office for neglect of duty, malfeasance, misfeasance, extortion or corruption in office, incompetency, or intemperance in the use of intoxicating liquors or narcotics to such an extent, in view of the dignity of the office and the importance of its duties, as to render the commissioner unfit for the discharge of the duties, or for any offense involving moral turpitude while in office committed under color of or connected with the office.