Another theory is working its way around the corner. According to this version, last Friday's General Election result was a freak result. If the PAP government had lost enough seats to boot it out of government, we'd call it a freak election result. But when the PAP wins so convincingly against expectations, is this not also a freak result?
There are people digging into various numbers and some have come up with the hypothesis that the swing originated from a particular group of people called new citizens. The assumption is that new citizens became new citizens because they liked what they saw, they liked the way Singapore is organized and governed, and they see it as a permanent home. So it is quite natural for them to vote for the PAP. The question is, how many of these became new citizens since the last election and voted in GE 2015? For a start, there was an increase in the number of voters in GE 2015 - 2,304,331 to be exact. In GE 2011, the total number of registered voters was 2,060,373, making a difference of 243,958. This is a 11.8% increase. The number of spoilt votes in both GE 2011 and 2015 is more or less the same, around 2+ %. Given Singapore's declining birth rate over the last 20 years, the net increase in number can only be attributed to immigration/emigration. Obviously, an increase means there were more people coming into Singapore than going out. Thus the major component of the increased voter numbers can be attributed to new citizens in the last 4 years. Would these have caused the swing towards the PAP? Possibly.
This is a sketch of the new citizen hypothesis, but it does suggest that 'old' citizens may not have contributed as much to the PAP votes as has been assumed so far.