My analysis is this:
Some 5% voters who didn't like WP and PAP have given their vote reluctantly to SDA because they have no other choice unless they spoil votes.
With RP stepping into the fore, SDA votes may further be diluted because Keneth is more learned compared to Desmond LIm.
Thus Desmond might not perform better than the last election. Expect his deposit to vanish as treat for PAP to lim kopi.
WP votes of 41% may also be diluted by RP presence, thus I expect about 35 vs 20 share of votes....
PAP 54% votes is marginal, its scandal and poor performances may cost them some votes. Rightly it should go to WP but RP presence is stealing the swing vote.
The last presidential election result is likely to be repeated here, imagine the following:
Tan Kin Lian - SDA
Tan Cheng Bock - WP
Tan Jee Say - RP
Tony Tan - PAP
Past the post - PAP is sure the winner, at close margin with WP.
RP & SDA WILL NEVER WIN even though they may have supporters, but not big enough to topple PAP voters.
Verdict: Not wise to have 3-corner fight, let WP trash out with Pap.
RP