I am aware of some US citizens being deported by mistake under previous administrations, but there was a general consensus that those were genuine mistakes, examples of negligence rather than policy: https://immigrationimpact.com/2021/07/30/ice-deport-us-citiz...

However the current administration is explicitly considering the idea of deliberately deporting citizens: https://www.msnbc.com/deadline-white-house/deadline-legal-bl...