President Fidel V. Ramos, due to a constitutional prohibition against Arroyo from making appointments two months before the election up to the end of her term. Before being elected president, Aquino said that he will not recognize any chief justice appointment that will be made by the Arroyo administration, and mentioned impeachment as an option to remove him by saying "The legislature has the power of impeachment if they feel there are grounds to impeach an impeachable constitutional body. That is open to any president... Therefore we will have to restudy the matter, study our options. At this point in time Congress has yet to be elected." However, an earlier Supreme Court decision in Arturo M. De Castro v. Judicial and Bar Council, et al. on March 17, 2010, upheld Arroyo's right as incumbent president to appoint the Chief Justice. Voting 9–1, the high tribunal underscored that the 90-day period for the President to fill the vacancy in the Supreme Court is a special provision to establish a definite mandate for the President as the appointing power and that the election ban on appointments does not extend to the Supreme Court. Corona abstained from ruling on the case together with Chief Justice Puno and Associate Justice Antonio Carpio while Associate Justices Antonio Eduardo Nachura and Presbitero Velasco, Jr. dismissed the petition as premature. Associate Justice Conchita Carpio-Morales, in her dissenting opinion, stressed that the Court can function effectively during the midnight appointments ban without an appointed Chief Justice. Senator Miriam Defensor Santiago, a constitutional expert, warned critics of the Corona's appointment to obey the rule of law, saying that the appointment of Corona has already been laid to rest under the doctrine of res judicata, meaning that it can no longer be relitigated in court, because it has already been decided with finality. Further stating that "After the Supreme Court decision in De Castro v. Judicial and Bar Council last March, which settled the issue, any petition is now precluded, on the theory of so-called collateral estoppel," She also commented that "The problem with the critics is that they mistake the law as it is; with the law as it ought to be, according to their layman's interpretation. A line has to be drawn between the rule of law and the dystopian concept of freewheeling ethics," Doctoral degree controversy As part of the well-orchestrated and well-funded attack on the Chief