France is on the cusp of voting in a far-right government for the first time since World War II, as the national mood appears to be souring on President Emmanuel Macron’s brand of mainstream centrism and lurching toward fiery anti-establishment populism. It’s a familiar story for anyone watching the political drama from the bitterly polarized U.S.

France’s anti-immigrant National Rally party is edging out the competition in opinion polls in the run-up to a two-round snap legislative…