I think that it is really very silly and childish of the supporters of Mr Tan Jee Say to heckle Dr Tony Tan. After all, if Dr Tan is so well-qualified as to even be able to run for presidency, what position are the supporters to heckle him? Also, they need to learn to not do to others what they do not want others to do to them. I am sure that they would not like it if they were giving a speech and the audience was booing them. Furthermore, this would leave others with a bad impression on Mr Tan Jee Say(no offence) on the type of supporters he is attracting, thus affecting his chance of getting elected as President. Also, if foreign visitors witness this scene, think of the impression this would make on them when they see that even elections for presidency resemble a wet market.
On the other hand, I think that it is very good that the other candidates, including Dr Tan himself, is handling the situation extremely well. Instead of lashing out at the hecklers, Dr Tan instead just simply says that "while different points of views are to be expected in a campaign. he was disappointed that some refused to listen to another candidate", according to the article. This is very true. Also, his attitude is very good. He does not show signs of being perturbed by the hecklers, showing that he probably is confident of his chance of becoming President, hence he is not affected by the hecklers. After all, let the hecklers heckle! Let them do whatever they want! In the end, the result is then what matters, and by heckling, the hecklers are just disgracing themselves in public.
I think that if the hecklers boo Dr Tan just because they do not like him, then the booing is really unreasonable and childish. However, if they really think that Dr Tan is unsuitable for presidency because of some particular reasons, they also should not boo him. If he really is unsuitable, he will not be able to win the votes of others and in the end, not be elected as President. At the end, the facts will come into light as to who is the most suitable and is able to win over the hearts and eventually the votes of the majority of the voters.