Macron called a snap election for the FRENCH legislature in the hopes of using “Far right is winning, SUPPORT THE NON-FAR-RIGHT” (implicitly, Macron’s centrists) to renew his mandate to rule.
However, the far-right won big in the first round of elections, sending everyone into a panic, since they were projected to get close to or an actual majority in the French legislature.
Macron and the Left then agreed that in races where both of their candidates were competitive, the weaker of the candidates in each of the races would drop out to bolster the other, because as much as they hate each other, they hate the far-right more.