In a large bowl combine the slow cooker barbecue chicken, barbecue sauce, corn, rice, black beans, and red onion, garlic powder, salt, and black pepper.
Add 1 cup of cheddar cheese and mix until well combined.
In a 9×13 inch casserole dish spread the mixture into an even layer. Top with the crushed tortilla chips and remaining ½ cup cheese.
Bake for 30-35 minutes or until casserole reaches a minimum internal temperature of 165 Degrees F.