I assume it has to do with the fact that along the equator it’s typically warmer and the equator runs through the northern part of South America. So if temperatures go up they’ll go up there first and head north south respectively. I don’t think they meant Souther Hemisphere as much as they mean Southern Mexico / South America.
Agreed we gotta vote blue down ballot in order for any real change to be possible. Im hoping that people realize what a threat the republican party has become to the very soul of what America stands for. So here’s hoping.