Article VII, Section 4 of the Constitution provides simply and unequivocally: “The President shall not be eligible for any reelection.”
The framers of the 1987 Constitution could not have made that sentence any clearer. The provision was intended to prevent a repeat of the Marcos experience. 
Ferdinand E. Marcos held the reins of executive power for 20 years, and was all set to add a few more until he was ousted extra-constitutionally in 1986.
President Rodrigo Duterte has been teasing the public about running for Vice President next year. Is this intended to circumvent the ban against presidential reelection?
There will be no time lag between two positions incase Duterte decides to run for the second highest position in the land. He will be campaigning with the full complement of executive power as a sitting President during the election period.
Christian Monsod is a living member of the commission that drafted the current Constitution. He said that for the President to run for vice president is against the intent of the Constitution. He calls it “an insidious move to circumvent the constitutional prohibition on reelection because the Vice President is the mandatory line of succession to a vacancy.”
Monsod explained that “if you allow the President to run again as Vice President, that vacancy can be created for a self-serving purpose, which is exactly what that intent is.”
Former Integrated Bar of the Philippines president Domingo Cayosa takes the contrary view, i.e., that there is no legal impediment to the vice presidential candidacy of President Duterte. “The Constitution does not explicitly prohibit a president from running for another office after his term as president. What it prohibits is reelection,” Cayosa said.
The President may have been joking all along, as is his wont, but here we have at least two top lawyers disagreeing on the interpretation of the Constitution. Is there truly a need for an express prohibition to disallow a sitting president from running as vice president in the next elections?
An example may be cited. The Constitution does not ban suits against a sitting president. Yet our courts routinely dismiss cases filed against the President on the basis of mere doctrine – presidential immunity from suit. This doctrine proceeds from logic and convenience. A President must be allowed to perform his functions without being hobbled or distracted by suits constantly questioning his every action.
Thus, does the fact that the Constitution is silent necessarily mean that a sitting President is allowed to run as vice president?
It is easier to visualize this with extreme cases.
Section 7 of Article VII of the Constitution provides thatif the President-elect fails to qualify, the Vice President-elect shall act as President until the President-elect shall have qualified.
What if Sen. Bong Go runs and wins the presidency along with President Duterte as his running-mate? What if for one reason or another Go refuses to take his oath and therefore fails to qualify?
The same section provides that if a President shall not have been chosen, the Vice President-elect shall act as President until the President-elect shall have qualified.
What if for one reason or another by June 30 next year the canvass of votes is not completed as to the presidency but completed as to the vice presidency and Duterte is proclaimed as the winning candidate?
The other extreme case is death or permanent disability of the President-elect. In which case, the vice president ascends in full capacity as president.
In all those cases, the six-year term limit intended by the Constitution as a buffer against long-running presidencies is defeated.
Of course, the more practical question is – will the Commission on Elections dodge the constitutional question in the event that a disqualification petition is lodged before it, and proceed to include Duterte’s name in the ballots?
Your guess is as good as mine./WDJ