In politics, and other areas, to surge is to accelerate forward rapidly, while to ebb is to decelerate backward rapidly.
You can surge to make relative progress without making absolute progress, and vice versa.
Example: "The Washington Redskins surged back from behind but lost the game to the New York Jets by 2 points." The surge did not result in victory, but resulted in narrowing the 20 point gap by which the Redskins had been behind at halftime.
Example 2: "