The Macapagal administration had been wracked with defections in the run-up to the 1965 polls—the most prominent being Senate President Marcos, who had bolted the LP to join the NP. Vice President Pelaez, despite having been earlier booted out of the NP, had also quit the ruling LP and returned to the NP. Both Marcos and Pelaez subsequently put their names on the ballot for NP standard-bearer in 1965. Interestingly, the two new recruits were the frontrunners in the NP convention, with Marcos winning the nomination, while Pelaez decided to run for his old Congressional seat in Misamis Oriental. Senator and former Vice President Fernando Lopez, another former Liberal, was chosen to be Marcos’ running mate.
After the Nacionalistas, it was the LP’s turn to nominate their bets for 1965. President Macapagal was nominated for re-election and he chose Senator Gerardo Roxas, topnotcher in the 1963 Senate polls and son of the late President Manuel Roxas, to be his vice president.
A third party emerged called the Partido Pilipino, later known as the Party for Philippine Progress (PPP), with Senators Raul Manglapus and Manuel Manahan as its standard-bearers.
The three-way fight resulted in the victory of the Nacionalista ticket, with Marcos leading Macapagal by more than half a million votes. Lopez, however, won the vice presidency by a margin of 0.4% of the vote (or less than 27,000 votes)—the slimmest margin of victory ever recorded for a national post in Philippine electoral history.
The campaign was also noteworthy for having been a battle of campaign biographies and films. The Marcos camp published For Every Tear a Victory: The Story of Ferdinand E. Marcos, and produced Iginuhit ng Tadhana (Destined), while Macapagal countered with the release of Macapagal the Incorruptible and Daigdig ng Mga Api (World of the Oppressed).
In the Senate, the NP continued to dominate, with five of its bets winning against only two Liberals. One seat was won by Senator Lorenzo Tañada of NCP, then allied with the LP.
The Presidential Communications Development and Strategic Planning Office (PCDSPO) has published the Philippine Electoral Almanac, a handy resource on Philippine national elections from 1935 onwards.