It is a famous victory for the Workers’ Party (WP) and its candidate Lee Li Lian, and confirms the WP’s growing standing and stature not only as Singapore’s leading Opposition party but also its dominance of Opposition politics. It will catalyse Singapore’s rapidly changing political landscape, moving resolutely away from a “new normal” to a “more normal” state of affairs.

Despite a crowded race with four candidates, which included the Secretary-Generals of the Reform Party and the Singapore Democratic Alliance and a potential office holder in Dr Koh Poh Koon of the People’s Action Party (PAP), the WP stamped its class, authority and power.

What accounts for the WP’s stunning win, given that the by-election was one for the PAP to lose? Punggol East was not a secure seat for the PAP.

In the General Election (GE) in 2011, Punggol East was ranked a lowly ninth out of 12 in terms of victory margin for the PAP, only ahead of the marginal seats of Potong Pasir and Joo Chiat, and Hougang, where it had not won since 1991.

For the WP, the by-election effect worked its magic this time — voters felt that they had nothing much to lose by throwing their support behind a strong, credible alternative given that the outcome of this by-election will not affect the PAP’s control of the Government.

There was the added seductive charm of tactical voting that the WP advertised for: That Punggol East will have the best of both worlds with a WP Member of Parliament (MP) and a PAP grassroots adviser working for them in Punggol East.

Further, unsettled ground sentiments over hot-button issues such as housing prices, transport woes, immigration, cost of living and the income divide meant that the addition of another WP MP could press the PAP Government to do more and even faster in order to stanch declining popular support for the ruling party.

Another key reason for the WP’s success was its ability to get swing voters on its side, and to have voters who wanted an Opposition MP to cast their ballots in favour of the WP.

This enabled the WP to gain a massive swing of votes from 41 per cent in GE 2011 to 54.5 per cent yesterday — all in a mere 20 months.

The WP’s margin of victory meant that it also won over many voters who had voted for the PAP in May 2011.

That the by-election was a four-cornered contest was a blessing in disguise for the WP. It resolutely concentrated voters, particularly those who wanted to vote for the Opposition.

The WP’s cachet meant that such voters decided to pool their support behind Ms Lee.

So it is no surprise that Mr Kenneth Jeyaretnam and Mr Desmond Lim lost their electoral deposits and incurred significant damage to their political reputations.

With this victory, the WP will be able to catalyse its plans to be an even bigger player in the next GE.

It will boost the WP’s recruitment and fund-raising efforts. They are well-positioned to make further inroads in the next GE, although they will have to manage the other Opposition parties which are naturally concerned about being overwhelmed by the WP juggernaut.

We can also expect the PAP to respond robustly, but it will have lots of soul searching to do in the meantime.

Eugene K B Tan is assistant professor of law at the Singapore Management University School of Law, where he regularly teaches ethics and social responsibility. He is also a Nominated Member of Parliament.