If any such presidential elector shall die, or for any cause fail to attend at the seat of government at the time appointed by law, the electors present shall proceed to choose viva voce a person of the same political party as such deceased or absent elector, to fill the vacancy occasioned thereby, and immediately after such choice the name of the person so chosen shall be transmitted by the presiding officer of the college to the Governor, who shall forthwith cause notice in writing to be given to such person of his election; and the person so elected (and not the person in whose place he shall have been chosen) shall be an elector and shall, with the other electors, perform the duties enjoined on them.