Something remarkable is happening in France: Emmanuel Macron is becoming popular again. Recent polls show the French President’s approval ratings rising from their late-summer trough, a rare feat in French politics.

The Ifop-Fiducial poll released last week is most striking, with Mr. Macron’s approval rating now back to 50%, up six percentage points from November. Neither of Mr. Macron’s two immediate predecessors, François Hollande or Nicolas Sarkozy, managed to claw back to that level after they fell below it. A similar...