No correlation.
2011 - Population White Paper (Mass importation of foreign talent from 2007 - 2011, resulting in improvement in quality of opposition candidates - Lee Li Lian, Hazel Poa, Nicole Seah, Gerald Giam, Chen Show Mao, Pritam Singh entered their first ge. First time LTK changed the entire image of WP... and won Aljunied GRC.
2015 - LKY effect, emotions run high after his death and all the hype with SG50. Many decided to give PAP a second chance. They also realised that many are unhappy with them after the mass import, scale down a bit.. 2013 saw WP winning Punggol east in a by election despite a three way fight.
2020 - COVID effect. Candidates werent as strong as 2011's candidacy. Due to Covid, opposition also didnt manage to get enough quality candidates to contest.
2025 - High cost of living, everything going up. Rising rentals caused many restaurants and SMEs to close down... HDB flat prices soar during COVID and never came back down.... HDB BTO also cost around $100,000 more as compared to 5 years back. Jobs scarce again as economy grew, PAP again mass import FT, fast track all the digital passes... if you are fresh grad, you are basically screwed... So we are talking about back to 2011 situation, just that time round no boomers to help them. (-5% boomers after many die enmass due to covid and age related.) 2021 also saw population decrease as many new citizens pack up for better pastures. Gaza issue seems to affect our local muslims somehow and with the ex NMP controversy things arent looking good.