Our election data reporter Christine Zhang explains how double-digit swings in several counties helped Dr. Annie Andrews, a Democrat, defeat Senator Darline Graham, a Republican, flipping South Carolina in the U.S. Senate race.

Our election data reporter Evan Reynolds looks at counties that could decide the Senate race in the diverse and rapidly growing southern states of Georgia and North Carolina.

Could Texas elect its first Democratic Senator in decades? Our election data reporter Christine Zhang tells us what counties to watch in the competitive Texas Senate race.