The party was created as a political movement in 2008, by Senator Alejandro Navarro, after the then member of the Socialist Party (PS) began to feel poorly represented both by his party (which was then headed by Camilo Escalona) as the Concertacion, political coalition that owns the PS.

In 2009, after a failed presidential campaign, Navarro and the MAS members offer support to candidate Marco Enríquez-Ominami.

[3] For the presidential election of 2013, however, announced it will support Michelle Bachelet (PS), representative of the former Concertacion.

[4] In 2014 it merged with the Northern Force Party, led by the mayor of Iquique, Jorge Soria, to form MAS Region.

[7] The following is a list of the presidential candidates supported by the Broad Social Movement.