He had democratic, anti-authoritarian ideas, and in 1868, he joined Adolfo Alsina's Autonomist Party, where he showed a skill for incisive rhetorics in public debates.

When the bill was passed by the legislature, Alem resigned his seat and became the intellectual leader of a group of discontents that sought to produce changes in Argentine politics.

In 1889, Argentina was going through a deep political and economic crisis, worsened by the corruption and abuse of power of President Miguel Juárez Celman.

When Vice-President Carlos Pellegrini took charge in his stead, Alem renewed his opposition, lending support to uprisings against the national government in the provinces.

[3] There are two cities called Leandro N. Alem in Argentina, one in the province of Misiones and another one in the north-west of Buenos Aires (with the same name as the partido where it belongs).