In 1940 he was among the minority of parliamentarians refusing to grant full powers to Marshal Philippe Pétain.

During the war, he was part of the central committee which reconstituted the Human Rights League and also co-founded the Brutus Network, a Socialist Resistance group.

Gouin's tenure was arguably most notable for seeing the enactment of France's first ever compulsory, amply funded retirement and worker's compensation laws.

[1] In addition, both the 40-hour law and overtime pay were re-established, while the comites d'entreprise (works councils) were extended to firms with 50 workers.

[3] Gouin's time in office also witnessed a significant extension of the role of the state in the workings of the French economy, with electricity, gas, coal, and the nine main insurance groups nationalized.