Twice this week I have read in prominent publications musings about whether or not Prime Minister Abe Shinzo could possibly still be in office at the time of the opening of the Tokyo 2020 Olympics.
Could Abe be the premier at the torch lighting ceremony?
In theory, yes. The only requirements for a prime minister are being alive and a member of the Diet (yes, I am aware that the latter presumes the former. Bear with me).
Prime Minister Abe is 58 years old, meaning that he will be 65 at the time the 2020 games. Abe's father Shintaro died at the relatively young age of 67 of undetermined causes -- explanations including heart failure (the official cause of death), liver failure and cancer. Shinzo has also had health problems, the nature of which are the subject of speculation (secrecy about health issues seems to run in the family). Shintaro's death came after a two year period of hospitalization -- a collapse and sudden withdrawal from public life seemingly triggered by the shuddering halt in his career brought about by the Recruit Scandal (another parallel - Link).
While the robustness of Abe Shinzo's physical health has a question mark over it, there should be no questions about his political health. Yamaguchi Prefecture is the home of conservative elective politics and a Liberal Democratic Party (all six Diet members) and Kishi clan (Abe's younger brother Kishi Nobuo is the representative for Yamaguchi District #4) bastion. Abe will continue to win in his Yamaguchi #2 district as long as he is running for a seat.
Nevertheless, the charter of the LDP pretty much rules out Abe presiding over Olympics in 2020. Article 12 of the charter sets the term of the presidency of the LDP at three years, with a maximum of two consecutive terms in office (Link - J). While there is no stipulation that a prime minister must be the head of a party, the general consensus is that only the heads of parties are eligible for the prime ministerial election. Murayama Tomiichi became prime minister even though he was not the leader of the largest party in the Diet. He nevertheless was at least the leader of the soon-to-be-doomed Socialist Party.
In the already unlikely event Abe Shinzo manages to serve out two full terms, he will lose his party presidency. This will mandate his resignation as prime minister.
Abe could, of course, return to the LDP presidency after the term in office of a successor. However, it is extremely unlikely that the members of the LDP, or more specifically the many prime minister wannabees in the LDP, would let Abe have a third chance at the party's top post. It is even more unlikely that Abe would run for the premiership as an independent or the head of a party other than the LDP.