The coup staged by backers of Sen. Juan Ponce Enrile to depose Sen. Manuel Villar from the Senate presidency places Enrile in a strategic position that has historically been the staging ground for a challenge to presidential power.

In at least two instances, the incumbent president who was seeking reelection faced challenges from Senate presidents. In 1949, Senate President Jose Avelino mounted a challenge to President Elpidio Quirino from inside the Liberal Party. The challenge divided the party into the Quirino and Avelino wings. Quirino crushed the challenge and emerged as the Liberal Party presidential candidate and won the election against the Nacionalista Party’s Jose P. Laurel in an election marred by charges of widespread election cheating.

In 1965, Senate President Ferdinand Marcos took the same route and challenged President Diosdado Macapagal of the Liberal Party who was seeking reelection. Marcos, who switched to the Nacionalista Party and became its standard-bearer, defeated Macapagal.

The history of the Senate presidency as the staging ground for the presidency started in 1916 under the Jones Law (which created the Senate) when Manuel L. Quezon challenged the political supremacy of the speaker of the Philippine Assembly, Sergio Osmeña.

After Marcos, there have been coups on the Senate presidency, but not challenges to the incumbent in Malacañang from the Senate president.

One reason for the strategic advantage of the Senate presidency as staging ground for the capture of Malacañang is that the Senate president is third in the line of constitutional succession. In terms of powers, it is even more powerful than the office of the vice president, who merely waits (and prays) for the president to die, or be incapacitated.

The current imbroglio over the ouster of Villar makes Enrile’s accession special. Enrile has not announced his intention to challenge President Gloria Macapagal-Arroyo, who is theoretically at least serving out her elected term in 2010. He is therefore not a threat to President Arroyo, and there’s no reason for them to be rivals in 2010, a fact that makes it easier for them to remain allies and for the President not to be overly worried of Enrile plotting to undermine her.

Enrile’s occupancy of the Senate presidency is what raises questions over his political plans for 2010. Whether he will make a bid for Malacañang is the biggest question mark of the day.

With President Arroyo presumed to make an exit in 2010, the presidency is up for grabs among at least a dozen pretenders. None of the pretenders from the Senate, including Senators Manuel Roxas, Loren Legarda, Panfilo Lacson, the deposed Villar, and Richard Gordon, enjoys the strategic advantage of holding the Senate presidency. Without having to announce or reveal his intentions for 2010, Enrile now is situated in the position of kingmaker. The ouster of Villar has removed him from a position of competitive advantage over his announced rivals, and this is the compelling reason for his rivals to form the core group that instigated his removal.

But if President Arroyo is incapacitated or deposed by a coup or People Power before 2010, where would it take Enrile? A coup or People Power insurrection would put Enrile in a situation where he would thrive best. This is what makes him dangerous. That makes him a threat to all presidential pretenders, looking forward to the elections as the route to the presidency. The electoral system is not Enrile’s preferred route to the presidency. Coups provided him with opportunities to grab power in 1986 with his boys in the Reform the Armed Forces Movement (RAM), following their rebellion against Marcos and Enrile’s betrayal of Marcos at the Camp Aguinaldo military general headquarters.

Up to now, Enrile has never given up the belief that the civilian-backed people power uprising in 1986 robbed him of the opportunity to seize Malacañang and that the overthrow of Marcos is owed to the military revolt, not to the civilians who responded to the call of opposition leader Cory Aquino and Jaime Cardinal Sin who called on the people to save the lives of beleaguered military rebels holding out in Camp Aguinaldo and later in the Camp Crame police general headquarters. Enrile has never acknowledged that people power saved him and his cohorts from possible slaughter by Marcos loyalist forces led by Gen. Fabian Ver.

The electoral path to the presidency has frustrated Enrile’s ambitions, but he has not been any more successful on the path of coup-making. The Aquino presidency, which Enrile has never recognized as legitimate, was plagued by several coup attempts mounted by Gregorio Honasan’s RAM boys associated with Enrile. And Enrile has gone a long way since 1986 to reintegrate himself into the civilian milieu of parliamentary democracy.

In the Senate shake-up that ousted Villar, Enrile was installed as Senate president not because he plotted it, or because President Arroyo had a hand in it or former President Joseph Estrada hatched the coup. It is correct to say that the confluence of events was behind Enrile’s election. There was no grand conspiracy behind the coup. The clashing ambitions of several presidential aspirants facilitated the coup.

But we must remember that this confluence has put Enrile in his twilight years in a position of enhanced power and influence where he can swing the balance during a crisis. The demons of authoritarianism are lurking behind Enrile who is embedded in a democratic institution.