Think of all the people that Donald J. Trump has offended so far.
What are the traits of a good leader or a politician? Think of Abraham Lincoln, think of Nelson Mandela, think of Martin Luther King, think of the founder of Pakistan, Mohammad Ali Jinnah, think of Jesus. Now, think of Donald J. Trump, and his big mouth, and the way it moves when he boasts about how rich he is, and then insults everyone he feels is not important to him or his victory.
I'm sure you must have or have had a grumpy, ill-mannered, bullying kind of a person, somewhere in your neighborhood, who just assumes you are going to be in his way making his life more difficult. That is him. That is Donald J. Trump. He is your nasty neighbor.
If he became the President, he will most probably nuke any country that offends him or upsets him in any way. The way he tosses people off the stage, and humiliates people he dislikes in some way, during his campaigns, and then he has them kicked out of there; that very same way, he will deal with countries, thus isolating the United States from the rest of the world, and that will not be such a good sight.
Trump is lethal for the people of the United States. All he can do is, to hate and go to war. He will be the worst thing that will ever happen to the United States, and probably the best thing to the rest of the world.