What exactly is a "structural majority"?

What exactly is a "structural majority"?
If you take the structure of the Democratic Party, stuff it with people like Suk-yeol's lackey, Myung-bak's lackey, Nak-yeon's lackey, Hye's lackey, and so on, mix in some insurrectionist forces, and then line up the existing supporters led by Min-seok to shove them in, is that a "structural majority"??
Since when did we start calling a food waste bin a "structural majority"??
It seems like Jae-myung even eats meals made of a "structural majority"?