The machines have already taken over, even without AI. This is because everyone instantly believes what a machine tells them, no matter what. Look at people who have had their identity stolen. A machine says they took out a loan here, and a loan there. Now the creditor is demanding payment. The victim can't convince the creditor that they did not take out the loan because the machine says they did, and the machine is never wrong. Despite the fact that there is no physical evidence that any loan was ever granted to the victim, the machine is believed over the human. No one ever questions how the data got into the machine. No one ever assumes that any mistake was made at any time. Whatever the machine says is assumed to be the truth.
Recently, a friend related this story. He was at a checkout line at Target, and had purchased about $60 worth of items. He handed the clerk a $100 bill. The clerk mistakenly keyed in an extra zero, and the machine dutifully informed the clerk to make change of about $940. The clerk, without hesitation, started to do this and my friend had to stop her and explain her mistake. The clerk couldn't understand. They eventually had to call a manager over to explain the problem. This girl was prepared to do whatever the machine told her, despite the fact that it didn't make any sense.
We don't need AI for the machines to rule over us.