If the top 5 opposition parties - minus WP - can't forge a coalition, that itself is a statement that these opposition parties are pretty darn useless.
The top 5 parties should be able to put their egos aside and work together to defeat the PAP. If they can do that, sinkees will support them.
Given the mediocre track record of the PAP over the last few years, it is not difficult to toss them out. Strong messaging is the key.
Can the top 5 opposition parties show us that they are ready to take over?