That playbook is partly borrowed from André Janones, the Brazilian lawmaker who used the messaging app to mobilize supporters of President Luiz Inácio Lula da Silva ahead of his surprise reelection last month.

It has at least one obvious limitation: Political parties have no control over social media algorithms. In Brazil, Lula’s campaign alleged that Meta, which owns Facebook, WhatsApp and Instagram, was boosting Bolsonaro and suppressing its content — an allegation Meta denied.

Hadrien Clouet, a France Unbowed MP who closely tracks South American politics, said lessons would need to be drawn on how the Mélenchon campaign can “protect [itself] from the influence of U.S. social networks.”

But the underlying idea of having the young convince — if not pressure — their elders has been pushed by the movement’s leadership for several months already.

At a party event over the summer, Mathilde Panot, France Unbowed’s top lawmaker in parliament, invoked the work of French political scientist Vincent Tiberj, who has studied “inverse socialization,” or how children challenge and sometimes change their parents’ views and politics.

She pointed to the 2024 vote to make abortion a constitutional right in France, saying that several lawmakers were pressured into voting in favor of the proposal by their daughters — a point French media also reported at the time.

“The children need to convince their parents,” Panot said. “We need to do some grassroots work, to go out and convince people one by one, and that starts with our inner circle: parents, brothers and sisters, uncles and aunts.”