Further if you want to analyse who is good at speaking, a lot depends on the listener. Some listeners like the speaker to speak with an Oxford tongue. So if the speaker received his education in UK, he has an advantage. Incidentally, are most people aware that in UK, there are illiterate people who can speak perfect English but cannot read and there are people who can speak and read well but cannot count? Very likely these listeners would also appreciate the speaker to speak in long complex sentences, reminiscent of Victorian time. If he can mystify you with his speech, talking well above your head, that would be best.
On the other hand, there are listeners who like speakers who can entertain them in the most authentic Singlish. Anything less is a no no.
Basically, the successful politician must be one who understands his audience and where to touch base with them. Sometimes the same
tricks used too often can become stale and ineffective. Or try borrowing tricks from some other speakers. It can really fall very flat.
My thinking is that if Nicole Seah were to cry again in a rally, it will not have the same effect as before. For one thing, she is two years older and people don't expect such an older person to cry. That is why Lim Boon Heng's crying did not score the desired points.