The Delegate shall be elected by the people qualified to vote for the members of the legislature of the territory he is to represent at the general election of 1972, and thereafter at such general election every second year thereafter. The Delegate from the Virgin Islands shall be elected at large, by separate ballot and by a majority of the votes cast for the office of Delegate. The Delegate from Guam shall be elected at large and by a majority of the votes cast for the office of Delegate. If no candidate receives such majority, on the fourteenth day following such election a runoff election shall be held between the candidates receiving the highest and the second highest number of votes cast for the office of Delegate. In case of a permanent vacancy in the office of Delegate, by reason of death, resignation, or permanent disability, the office of Delegate shall remain vacant until a successor shall have been elected and qualified.