I would say Trump has another thing coming if he thinks his temperment is his biggest assest, it's quite the opposite. His temperment and ego make him unfit for the White House; he has insulted the other Republican candidates, belittled the parents of a Muslim veteran who won a Purple Heart and constantly makes bombastic comments, his most recent examples being, "I know more about ISIS than the generals", and telling the Mexican president, "I don't expect you to pay for the wall", only to say the very next day to America, "Believe me, they'll pay for it".
Yes, Trump is delusional if he actually thinks his temperament is his biggest asset. Trumps temperament is not his biggest asset, it's his greatest liability. He has called a whole race of people murderers and rapists, insulted women, and he makes up things about his opponents. Insulting people and being thin skinned are not characteristics of a great temperament.
The President of the United States is the face and voice of our country, but he/she is also a civil servant employed by the American people. It is every US citizens prerogative and civic duty to question the president's decisions and judgment. When Donald Trump's words are questioned or when he is in any way criticized, he becomes defensive. He overreacts and goes on the offensive. That is not presidential: it's dangerous.
Yes, Trump is delusional for many reasons, including thinking his temperament is his biggest asset. He speaks in third grade superlatives and riles up those Americans that are terrified of change and evolution. His biggest asset is being able to reach people who respond and connect to the hate and intolerance he spews at any given moment.
Donald Trump is not delusional by calling his temperament his biggest asset. However, Trump does hurt himself by giving voters the impression that he has a weak temperament. This perception hurts Trump with many voters that see him as unqualified to be commander in chief. Trump should do more to demonstrate to voters that he has the temperament to handle being president.