Every person running for presidency (or in fact every person that has a public speaking engagement) will have hecklers. Once you start engaging with them and being harsh on them it will create more hecklers and more haters. Donald Trump is already being viewed in a bad light for other reasons, he should not be trying to create more.
Donald Trump is going to have to be much more thick-skinned if he thinks he can handle being President of the United States. No President goes without getting heckled or facing opposition. He needs to control his temper - North Korea and Russia are going to be much tougher than some heckler.
I think that Donald Trump is too hard on everyone. I personally feel that he is a tool and that he should not have gotten this far in the first place. He completely disrespects anyone who does not hold his narrow views. On one occasion, he told rally goers to 'get a heckler out of here.' What I witnessed came across as a modern day lynching. Donald Trump is a racist fool and his success is indicative of the lack of progress in the contradicting country.
Nothing can get the blood boiling like politics, but, when it comes to how people conducted themselves, lines often get crossed. Trump has had his fair share of people shouting and interrupting when he's trying to get his point across. Any person with self-respect would defend themselves. One of the biggest things America now lacks is how we conduct ourselves in public and toward our leaders, regardless of our own views.