Mr. Hunt believes that he is the president of the united states and that he will soon become the ""king of the universe."" mr. Hunt is most clearly suffering from

Delusional disorder

Explanation:

Delusional disorder is classified as a psychotic disorder, a disorder where a person has trouble recognizing reality. A delusion is a false belief that is based on an incorrect interpretation of reality. Delusions, like all psychotic symptoms, can occur as part of many different psychiatric disorders. But the term delusional disorder is used when delusions are the most prominent symptom.

A person with this illness holds a false belief firmly, despite clear evidence or proof to the contrary.