No employee of the Corporation Commission in the unclassified service, shall, directly or indirectly, solicit, receive, or in any manner be concerned in soliciting or receiving any assessment, subscription or contribution for any political organization, candidacy or other political purpose; and no employee of the Commission in the unclassified service shall solicit or receive any such assessment, subscription or contribution from an employee in the classified service. No employee of the Corporation Commission in the unclassified service shall be a candidate for nomination or election to any paid public office, or take part in the management or affairs of any political campaign, except to exercise his right as a citizen privately to express his opinion and to cast his vote.