Destruction of American system

Why does the Republicans want to destroy our gains that we have gained over the last 100 years. Is it possible they want to make us slaves like in the Roman Empire day. If they do that then what is going to happen to the great Economy that we have built up. I admit that we can no longer afford to go to war may that is the reason that we needly need a world Government. Right now we are not only fighting big business but Religions that fight one another. But what I do?