The present Constitution imposes only three requirements to be elected President of the Philippines:
One must be 40 years of age on the day of election;
One must be a natural-born Filipino citizen;
One must be able to read and write.
For example, there are basically two eras: 1935 to 1969 (the last pre-martial law presidential election) and post-1986 to the present. In the first era, Ramon Magsaysay, the lone non-lawyer prior to 1969, would be in many ways the major exception to the expectation of a long, sustained, record of public service beginning in local, then provincial, and legislative and executive positions. But in many ways he was the harbinger of our modern, post-party machine politics, and so ties in to the post-1986 trend Marcos helped launch by means of institutionalizing mistrust of lawyer-presidents.
Of the twelve presidents elected in national elections, the following observations can be made.
Education: seven were lawyers (all of whom were top ten in the Bar exams); two had degrees in economics; two had doctorates; only one didn't finish college.
Pre-profession: Aside from their main professions, six had other professions/occupations, including two poets.
Military: Five achieved officer rank in the military.
Judicial: none served in the judiciary.
Legislative: three served as municipal councilors; eight have served in the lower house, with four serving as committee chairmen, and two of them as Speaker of the House; eight have been senators, and three have been Senate President, and two, Senate President Pro Tempore.
Executive: One has served as mayor; five have been provincial governors (including Magsaysay's serving as Military Governor of Zambales); nine have held presidential or executive appointments in the bureaucracy or civil service; in addition, seven have held cabinet portfolios, with two each holding the National Defense and Foreign Affairs portfolios. Six have been elected Vice-President, four have succeeded to the presidency from that position (three by virtue of the death of the president, one by authority of the Supreme Court).