G.R. No. 195649 - Maquiling vs. Commission on Elections

Natural-born Filipino who lost his citizenship upon naturalization as a U.S. citizen.
Re-acquired Philippine citizenship under R.A. No. 9225 by taking the Oath of Allegiance on 10 July 2008 and again on 3 April 2009, when he also executed an Affidavit of Renunciation of his U.S. citizenship.

Bureau of Immigration records show Arnado used U.S. Passport No. 057782700 on trips: 14 Apr–25 Jun 2009 and 29 Jul–24 Nov 2009, prior to and around issuance of his Philippine passport (18 June 2009).
Filed his Certificate of Candidacy for Mayor of Kauswagan, Lanao del Norte on 30 November 2009, declaring himself a Filipino citizen who had renounced foreign citizenship.

Opponent Linog C. Balua filed a petition on 28 April 2010 to disqualify Arnado for lack of residency and foreign citizenship, attaching BI certifications and travel manifests.
COMELEC First Division (5 Oct 2010) treated it as a disqualification case, held that Arnado’s use of his U.S. passport negated his renunciation, disqualified him, annulled his proclamation, and applied the order of succession under Sec. 44, LGC.
Arnado filed a Motion for Reconsideration; intervenor Casan M. Maquiling (second placer) sought proclamation. COMELEC En Banc (2 Feb 2011) reversed the First Division, ruled U.S. passport use did not undo renunciation, reinstated Arnado, and denied Maquiling relief.

Maquiling filed a petition for certiorari to review COMELEC En Banc’s finding that Arnado is solely Filipino despite continued U.S. passport use, and to be proclaimed Mayor as the second placer.

Whether a rival candidate may intervene in post-proclamation disqualification proceedings.
Whether the use of a foreign passport after renouncing foreign citizenship cancels the renunciation and affects eligibility to run for public office.
Whether the order of succession under Sec. 44 of the Local Government Code applies when an elected candidate is disqualified.