Well some Black Belt counties are colored in 50%, but all are green.
Yeah, but there are still white people in the black belt counties, sometimes close to a majority. I've looked at this referendum pretty extensively and the level of support for the amendment by county is pretty closely correlated to the percentage of black people.
The only big exceptions are Shelby County, just outside of B'ham which is normally extremely Republican but is also suburban and not quite as southern as the rest of the state. And then there's Huntsville, home to a large space and defense industry.
And to be fair, Gore actually did fairly well in some of the darkest red counties in the NW area of the state.
