The presidential dreams Joe Biden harboured since childhood seemed on the verge of extinction for a third, and final, time.
On an unusually cold late-winter morning in South Carolina, a few dozen people had gathered to hear him speak at a school gym.
He was getting clobbered by Sen. Bernie Sanders in the race for the Democratic presidential nomination. A virus, meanwhile, was on the verge of clobbering the United States.
Within days, on Feb. 29, Biden won South Carolina’s primary, forced most rivals out of the race and romped to one of the most head-spinning comebacks in American…
