If he is the only non-PAP candidate in a straight fight in my constituency, that's tough. Even if I dislike PAP immensely, there is nothing "opposition" about GMS even by rock bottom standards.
Position-wise, spends more than half his energy on the opposition (mostly WP but also on NSP and SDP). Character-wise, shown himself beneath any PAP or WP candidate. Would have been better if he doesn't talk so much and kept his long list of flaws hidden. Effort-wise, none to show. Getting into arguments because of exceptional but inaccurate views doesn't count.
You'd be better off with Zeng Guoyuan. At least his target and focus is clear.
