Rationale: Under Section 77 of Batas Pambansa Bilang 881, substitution of candidates in case of unexpected or fortuitous events is permitted so as not to deprive a registered or accredited political party the right to field its own candidate and effectively participate in the political contest. Politicians however, have often subverted the intent of the law by engaging in too much horsetrading, bargaining andf secret deals, sometimes with violent consequences. Hence, it is not surprising that most of thses politicians file their certificates of candidacy at the last minute.