On his first year at the University of the Philippines, Diliman campus he joined the Colegium Liberum (CL). He was also a feature writer of the Philippine Collegian, where he wrote articles critical of the Marcos administration. He was described by his contemporaries as an intellectual rebel. He played a key role in the formations of different nationalist organizations. From the formation of the Anti-Imerialist Youth Committee (AIYC), then as the founding Chairperson of a national youth and student umbrella organization, Youth for Nationalism and Democracy (YND) founded in August 17, 1980. He was elected chairperson of UP College of Arts & Science Student Council in 1982-83 then University Student Council (USC) in 1983-84. The establishment of the Center for Nationalist Studies (CNS) 1983.
He also played a key role in the formations of broad multi-sectoral organizations during Marcos Martial Law time. PAPA during the visit of Pope John Paul II in 1981. People's MIND in 1982 against the fraudulent Marcos national referendum. Lean’s leap from a university student to a full-time activist could be traced back however from the assassination of Aquino back in 1983. By joining in with the anti-Marcos ranks and the formation of JAJA (Justice for Aquino, Justice for All movement), he realized that through engaging in National Politics, he was able to learn more compared to remaining isolated in his classrooms. He dropped out of UP to lead street marches, speak in countless rallies and symposiums, and organized alliances with business persons, politicians, professionals, workers, and the urban poor to combat the Marcos regime. He was also part of the Kaakbay or Movement for the Philippine Sovereignty and Democracy, the group led by former Senator Jose Diokno and Nationalist Alliance for Justice, Freedom and Democracy (NAJFD) in 1984 . In 1985, the Bagong Alyansang Makabayan (BAYAN) was established and Alejandro became its secretary-general. Alongside Ka Bert Olalia, Lando Olalia, Crispin Beltran, Ka Pepe Diokno, Sen. Lorenzo Tañada and the other prominent Filipino nationalist leaders, Alejandro would be at the frontlines of the parliament of the streets during the 1980s.
During the eve of Valentine’s day in 1985, Lean and Jose Virgilio (J.V.) Bautista were arrested while they were negotiating on behalf of students marching to Camp Aguinaldo. Both were taken to Camp Ipil detention center in Fort Bonifacio. They were held on a Preventive Detention Arrest (PDA), a Marcos decree that authorized the detention of any person for one year without formal charges.
Inside the prison, Lean felt anxiety from a certain sense of helplessness. He yearned to be directly involved in the events of the times. As he said, “The struggle for freedom is the next best thing to actually being free,” in his letter to Lidy. Aside from his desire to go out and protest and the constant scorning received from the guards, life inside prison was bearable. Inside he continued to fight in the only way he was able to, through writing a two-page letter to his former mentor Professor Rita Estrada of UP-Psychology Department, which describes the conditions of his incarceration, his thoughts on Marcos’ dictatorship and how it “humiliates our people”, and finally emphasizing that “we must never utilize the cruel and barbaric methods of tyranny but rather fight like men, and not dogs or rats”. After 2 months, Lean and JV were released with the help of a sustained campaign for their freedom from both domestic and international groups.
Even after imprisonment, his spirit remained unbroken and immediately went back into the protest movement. Jojo Abinales wrote in Conjuncture in August 1992: “He was brilliant when he brought differing and contentious representatives of the different classes together and made them work as a team. He had the confidence of a leader but he also had the humility to admit mistakes and learn from others”.
The SAMASA Alumni has commissioned a video documentary to be released soon featuring Lean Alejandro ... the story ... the inspiration.