Mo. Rev. Stat. § 36.159
It shall be unlawful for any person to intimidate, threaten, command or coerce any employee of the state to engage in, or not to engage in, any political activity, including, but not limited to, voting, or refusing to vote, for any candidate or measure in any election, making, or refusing to make, any political contribution or working, or refusing to work, on behalf of any candidate. No employee of this state shall discriminate against, discipline or otherwise create a preference for or against any employee subject to such person's authority as a consequence of such employee's political belief or expression of such belief. Any person who violates the provisions of this section is guilty of a class three election offense as established in section 115.635, punishable by a term of imprisonment for not more than one year and a fine of not more than two thousand five hundred dollars, or both such fine and imprisonment. Any person convicted of a violation of this section shall lose such person's position in the agency.
§ 36.159, RSMo