[1] As the student leader at the Pontifical Catholic University of Chile, he participated in the 1927 riots against Carlos Ibáñez del Campo's dictatorship, which was deposed in 1931.

During the same year, Leighton was sent by the Minister Marcial Mora to Coquimbo to placate the local military riots supported by the population.

During this time he founded – along with his friends and associates, Eduardo Frei Montalva, Radomiro Tomic, and José Ignacio Palma – the National Falange which merged with the Christian Democratic Party in 1957.

[4] According to CIA documents released by the National Security Archive, Italian terrorist and neo-fascist sympathizer Stefano Delle Chiaie met with DINA agent Michael Townley and Cuban Virgilio Paz Romero in Madrid in 1975 to prepare for the murder of Bernardo Leighton with the help of Francisco Franco's secret police.

[5] Townley had admitted commissioning the murder attempt on behalf of DINA by members of National Vanguard, an Italian right-wing terrorist group.

This event brought about the end of his pacification intentions to reunite the various groups opposing Pinochet, including the leftists.