I do not think he really expects to win anything.
He has for whatever reason elected to raise his profile; most likely personal gains.
He does have a constituency that supports his views. That is how he gets re-elected.
He does get face time on the camera and that developes name recognition.
He does become more eligible for interviews, speeches, book deals, etc.

Plus if his staff counsels him correctly he can add value to whoever it is that becomes the front runner.