I believe it applies to state employees who are funded wholly or in part by federal monies. I am PA state employee. We have restrictions on the types of political activity which we can partipate in. There may very well be state laws or civil service rules that apply. It also may depend on his actual status in the state system.
My ex-wife, not being knowlegeable about this, lost her state job because she ran for school board. She tried to withdraw but her name was already on the printed ballot. As of election day she was canned.