The start of the historic impeachment trial of Philippine Supreme Court Chief Justice Renato Corona may play out to be a high-risk political move by President Benigno Aquino III, who remains popular in his second year in office.

The trial, which began Monday on live television, saw the Senate turned into an impeachment court to try Corona on charges of corruption, loss of public trust and other issues. It is the outcome of a battle, both political and personal, that began almost when Aquino was elected president in May 2010.

Many observers have attributed the Senate trial to the president’s drive to rid the country of endemic corruption, the theme of his campaign promise. But some thought it would end just there, as a promise.

Theoretically under the Philippines' constitution, the presidential palace plays no role in the impeachment process. The House of Representatives must decide exclusively to initiate the process and the Senate has the sole power of impeachment. It has been clear from the outset, however, that Aquino expended considerable political power in pushing the 188 members of the House to vote an impeachment proceeding.

“Some people close to him didn’t think it would go this far,” said a senior Cabinet member, who asked not to be named. After winning the election, “they thought it would be a ‘let’s move forward,’” focusing on raising economic standards. The idea of losing the impeachment case, although slim for now due to his high approval rating, could obviously weaken Aquino at such an early stage of his presidency, which ends in 2016.

But the president appears bent on making a change, perhaps an indication of moving out of the shadow laid out by his late parents, heroic leaders in the eyes of the people, and trying to undo his image of a slacker and an underachiever. After persuading a majority of the lower house to impeach Corona last month, he must now obtain the support of 16 of 23 senators to do the same thing in what would be the biggest gamble he has yet undertaken.

Although the separation of powers theoretically precludes Aquino from taking part in the process, the public clearly regards the scenario as a proxy battle between the president and his predecessor, Gloria Macapagal-Arroyo, currently under hospital arrest after she attempted to leave the country in November, apparently to evade facing criminal charges using health reasons.

The entire drama, according to one palace aide, forced Aquino to crack the whip against the Supreme Court, whose chief justice was clearly beholden to Arroyo and had attempted to permit her departure before she was stopped at the airport, wearing neck braces and parked in a wheelchair. The contest has played itself out in a variety of ways, with the high court blocking Aquino's attempts to appoint a "truth commission" shortly after his election to seek to bring Arroyo to justice.

After the president blocked Arroyo's attempt to leave the country by preferring new charges against her, the court reopened a case and voted to distribute Hacienda Luisita, a 6,435-ha sugar estate to its workers. The plantation is owned by the Cojuancgo family, the family of the president's late mother. The court, on a 14-0 ruling, also ordered Hacienda Luisita to pay the farmers P1.3 billion (US$28.7 million) from the Cojuancgo family’s sale of portions of land that were converted for industrial use.

The president is in a “game where he has put everything at stake,” said analyst Romeo Bernardo of Global Source Partners, a Manila-based think tank. “It’s a big risk for the country,” he added, in the amount of the president’s political stock and resources he could have to give in – if it would come to that – to senators looking into mid-term elections next year or possibly a handful of them harboring presidential ambitions in their own right.

“They haven’t made up their minds” regarding Corona, conscious of the public perception that the trial is viewed largely as a political exercise and not necessarily a judicial one, and despite the Senate’s decorum of impartiality on the first days of the hearings. Aquino told reporters he was confident of a victory, the charges raised being “solid,” first on the fact that Corona had been appointed by Arroyo during a ban in the election interim.

The Chief Justice pleaded not guilty to eight counts brought by the Lower House, whose chief prosecutor displayed a PowerPoint show of Corona’s luxury properties, allegedly acquired from ill-gotten wealth while in power.

Though not required to appear at the Senate court, Corona sat in the first row of the gallery with his wife, wearing a dapper suit. In a public rally earlier in which he and his supporters wore black, he played the part of the underdog, saying this was all part of a plot to get him out of the way and that he would fight to clear his name “until death” – which could foretell a long, bitter, divisive trial. (A former Supreme Court associate justice heads his defense team.)

The personal and the political aside, an impeachment could mean a lot more for the sake of jurisprudence, said Raul Pangalangan, former dean of the College of Law of the University of the Philippines. “If he (Aquino) wins this, it will re-calibrate the balance in the separation of powers,” placing the judiciary in its “proper check.”

That puts this issue in the context of recent history, in which the pendulum has swung from the years of martial law to a democratic transition: a new constitution drafted under the government of President Aquino’s mother 25 years ago gave the Supreme Court powerful judicial review as protection against fears of authoritarian rule, but in the process inadvertently slowed government reforms in a number of cases involving national policy, mining for one.

The Supreme Court meanwhile has been losing its moral ground over the past years, with some justices known for switching decisions, being susceptible to favors, lowering legal standards, and plagiarizing written court cases. Aquino may yet have to see the implication of his move in the long run; and “even if he loses, if the goal is to put them (the justices) on notice,” said Pangalangan, “he’s achieved that.”

(Criselda Yabes is the co-author with Marites Danguillan Vitug, Our Rights, Our Victories, a critical look at the Philippine Supreme Court. She can be reached at cdyabes@yahoo.com.)