Ce ralliement était attendu. Depuis plusieurs semaines, les membres du cabinet de M. Le Drian travaillaient main dans la main avec ceux de M. Macron. Son programme en matière de défense, dévoilé le 18 mars devant un parterre de gradés de l’armée, avait été entièrement conçu par des proches de l’élu breton.In other words, staff personnel of a regalian ministry are lending their expertise to a candidate whom the president must refrain, and has reportedly urged ministers to refrain, from publicly endorsing. Meanwhile, the Haute Autorité governing the Socialist primary has officially rebuked Manuel Valls for denying Hamon his parrainage after losing to him in the primary.
The French left is usually a contentious place, but this kind of open guerrilla warfare is something new (one saw it on a smaller scale when Ségolène Royal was the candidate and in a more covert form when Mitterrand was cutting the legs out from under Michel Rocard). But it is clear that les éléphants have decided to cut Hamon loose, are all in for Macron, and are no doubt already negotiating behind the scenes for a joint campaign with En Marche! in the legislative elections and for positions under the future President Macron.
The first post-debate poll has Hamon down a couple of points, moreover, so that the PS candidate could finish an unbelievable fifth after Macron, Le Pen, Fillon, and Mélenchon (in that order--Macron now leads Le Pen in round 1 in the same poll). In short, the party bearing the name "Socialist" seems to be dying, but a new center-left, or rather left-center-right, or perhaps more simply, "center" party is being born under the name En Marche!
The entire French Establishment (except for Fillon and his stubborn LR rump) is now all-in on Macron as the only alternative to Le Pen.
After the election, France could thus end up with an eco-socialist anti-European extragovernmental Left party, a Macronist Center Party, a traditionalist Right party, and a xenophobic Far Right Party. This would be a highly unstable mixture.