Preheat oven to 375 degrees F (190 degrees C). Grease a 9x13 inch baking dish. Bring a large pot of water to a boil over high heat. Stir in the rotini, and return to a boil. Cook until the pasta is slightly under-cooked, about 8 minutes. Drain well. Combine the processed cheese, tomato juice, and butter in a large saucepan over medium-high heat. Stir until melted and smooth. Mix the pasta into the cheese sauce; stir well. Transfer macaroni and cheese to the prepared baking dish. Top with the raw bacon slices. Bake in preheated oven until the bacon is cooked and crisped, about 30 minutes.