Wherever possible, the county clerk shall assign persons appointed as election board members to serve in precincts wherein they reside or in precincts located in the representative district wherein they reside. In the event of a shortage or absence of election board members in certain precincts, the county clerk may, in the best interest of the election process, assign appointed election board members to serve on any election board in the county; provided that such appointed board members shall not change the proportionate representation of each party on the board.