Moreno's supporters followed the American Socialist Workers Party in leaving the ICFI in 1963 to form the reunified Fourth International (USFI).

[1] While critical of the Sandinistas, Moreno's group sent a Simon Bolivar Brigade to Nicaragua to aid the Civil War,[2] with the aim of building a revolutionary party there.

[2] Almost immediately, Moreno's and Lambert's tendencies joined to form the Parity Committee for the Reconstruction of the Fourth International.

In addition to their former supporters, this also attracted groups in Peru and Venezuela which split from the Lambertist currents.

María Rivera was elected in district 8 (Santiago West) as part of The List of the People.