Why do southern evangelical Christians in American churches say "how that" instead of how?

Why do evangelical Christians in American churches say "how that" instead of how?

Ex. 1:

Let me tell you a story about Billy Beaumont and how that, for our sakes, he joined the war to fight the commies for our freedom.

Ex. 2:

Joey: Pa, why have our pecan trees lost all their leaves?

Pa: Well son, you know how that the woodpeckers will peck all kinds of holes in the trees?

Joey: Yep.

Pa: Well that kills the trees and that’s why they ain’t got leaves no more.

In my understanding, correct usage of "how that" would be:

Well Joey, I’ll you how that happened: woodpeckers killed the trees by putting all kinds of holes in ’em!

I had not heard the former usage in the two examples until I moved from Portland, OR to Alabama. Now I hear it everywhere, especially in the churches, but also just in casual conversation. I was just wanting to understand where that usage originated, what the reason for it is, and how widespread it is.