Bullitt County Sheriff fires second in command

That depends on whether he was speaking for the department on-duty and out of uniform, or if he was there speaking as a private citizen out of uniform. Giving an endorsement on a radio broadcast while speaking as Chief would seem to be the former.

5.1.1 POLITICS

Members shall not be active in politics or work for the election of candidates while on-duty. While off-duty and out of uniform, members may engage in political activity pursuant to the law.