In the case of PP it is no ordinary constituency where you look at the candidate and make a decision. The residents of PP have realised a long while ago that without the PAP their world would not cave in overnight despite what PAP claims. The dynamics is between the residents and the PAP rather than Lina. Lets not forget the sympathy votes that will go Lina's way. The old timers will also recall that Lina was with him from the very start and campaigned with him from the word go. Chiam miight have lost votes because of his party management and the failure to do succession planning but I am sure it is still be with SPP.
One of the reasons is that people living in the Sennet Estate, a predominently private housing estate, did not get much of the shares that the budget hand outs to citizens. Rich or poor, they happen to live in landed property, so they are heavily discounted from the distribution of the budget surpluses year after year. They can live with it. To them the gahment distribution meant the rich are getting poorer while the poor are getting richer - if living in a landed property is the sole criterion for the distribution of budget goodies.
But it shouldn't be so for the vast majority (>80%) elsewhere living in HDB flats - the gahment has helped them a lot - to the tune of billions! Be it their low pay, their allocation of more new HDB flats with as much as $60,000 grants, their upgrading which meant capital appreciation to their flats, etc. They should be grateful that they have such a benevolent government and should continue to support them for their future and more good years.
As to Lina Chiam, to be brutally frank, she is just an opportunist. Like the Indian and Filipino politicians who are actresses, she is just riding on the fame and sympathy of her husband. She is nowhere near Corazon Aquino - nor even Megawati Sukarnoputri. May be a little streak - like Jayalalitha Jayaram - san her beauty when she was younger.