In 1919, he joined the Socialist Youth Federation, where he quickly rose through its ranks after he participated in strikes and anti-fascist actions in the "Biennio Rosso".

Often not in line with Palmiro Togliatti's policy and sometimes considered as his possible alternative, in 1954 Secchia's position within the party began to weaken: in fact he was first joined and then replaced by Giorgio Amendola in the organizational direction.

Furthermore, the death of Stalin and his denunciation of the 20th Congress of the CPSU had made the position of the components that were linked to a more organically Marxist-Leninist vision (of which Secchia was the leading exponent) particularly uncomfortable both in the party and within the broader electorate of the PCI.

[1] Eventually, as a result of theft from the party's secret funds by one of Secchia's closest associates, he disappeared from positions of national importance.

In January 1972, he traveled to Chile, where he supported the government of Salvador Allende, making him the last Western leader to visit the Latin American nation before the advent of the dictatorship of Augusto Pinochet.