French president François Hollande suffered a damaging setback yesterday when France’s highest court ruled his proposed 75% “supertax” rate unconstitutional. The measure, which is blamed for an exodus of wealthy French abroad, was a pillar of the Socialist leader’s successful Spring election campaign. But in an unexpected blow, France’s Constitutional Council ruled that the tax band did not guarantee equality for taxpayers because two households with the same total revenue could end up with different tax bills. Although the tax would have hit only around 1,500 people, it was seen as the totem in Hollande’s political manifesto, which said it...