Cook the macaroni according to the package instructions.
In a large pot, melt the butter of medium heat.
Add the flour and stir for 1-2 minutes.
Add the milk, salt, and garlic powder and stir well.
Bring to a boil, stirring constantly and then reduce the heat.
Simmer for 2-4 minutes or until the sauce begins to thicken.
Stir in 4 cups of the shredded cheddar cheese until melted.
Add the cooked macaroni and mix well.
Cook the Mexican chorizo separately and add to the macaroni and cheese mixture.
Add a layer of the mac and cheese mix to an oven safe dish, and top with half of the mozzarella cheese. Continue with another layer of mac and cheese and top with remaining mozzarella and cheddar cheese.
Bake at 375 degree fahrenheit for 30 - 40 minutes.