G.R. No. 134577 , November 18, 1998.
SEN. MIRIAM DEFENSOR SANTIAGO and SEN. FRANCISCO S. TATAD, petitioners, vs. SEN. TEOFISTO T. GUINGONA, JR. and SEN. MARCELO B. FERNAN, respondents.

FACTS

This is a separate opinion by Justice Mendoza concerning a petition filed by Senators Santiago and Tatad against Senators Guingona and Fernan. The main petition involves a dispute over the election of the Senate Minority Leader. Justice Mendoza concurs in the judgment of the Court but dissents on the issue of jurisdiction.

ISSUE

Whether the Supreme Court has jurisdiction over the petition to determine if the Senate or its officials committed a violation of the Constitution or gravely abused their discretion in the exercise of their functions and prerogatives, specifically regarding the internal matter of who constitutes the minority entitled to elect the Senate Minority Leader.

RULING

Justice Mendoza opines that the Supreme Court has NO jurisdiction over this case. He argues that the question of who constitutes the minority in the Senate is a political question, pertaining to the internal affairs of a coequal department of government, and is thus addressed solely to the Senate itself. Courts have no power to inquire into the internal organization and business of a house of Congress unless the question affects the rights of third parties or a specific constitutional limitation is involved. He cites that the Court has previously declined jurisdiction over cases involving legislative discipline and internal rules. He distinguishes this case from instances where the Court took cognizance, such as Avelino v. Cuenco (involving a quorum requirement) and Tañada v. Cuenco (involving the composition of the Electoral Tribunal), as those cases involved the interpretation of specific constitutional provisions. In contrast, the present case involves neither an infringement of specific constitutional limitations nor a violation of the rights of a non-member of Congress. The Constitution leaves the election of “other officers” to each house. Therefore, Justice Mendoza votes to dismiss the petition for lack of jurisdiction.