Transport Minister Lui Tuck Yew's decision to quit politics has ramifications beyond the coming general election.
But to understand the broader issues, you have to look beyond the immediate problems with the MRT system and the angst associated with them.
It's tempting to attribute his shock announcement solely to his accepting responsibility for not being able to fix the train breakdowns.
But his decision exists in a wider context that isn't just about trains and breakdowns.
It's also about the role of a minister, the concept of collective Cabinet responsibility, and about the sort of people attracted to the job. So, what exactly is the responsibility of a transport minister?
In the business world, it's clear who is ultimately accountable for a company's performance - that's the chief executive officer.
Fail to deliver and the CEO's head is on the chopping block.
In politics, it can be more complicated because there are many other players involved, depending on what the issue is.
In the case of public transport, and specifically the MRT, the minister will be hard put to escape blame.
The system is built with taxpayers' money - costing tens of billions of dollars over many years - and is expected to perform and meet public expectations.
The Land Transport Authority (LTA), responsible for designing and building it, is a statutory board directly under the minister who appoints its board members.
But the people who run and maintain the trains and stations work for commercial entities, publicly listed companies that are also accountable to their shareholders.
It raises the question: To what extent can the minister influence what SMRT and SBS Transit do, especially in the critical area of maintenance?
To what extent was he able to and how much of a change could he effect in the way these operators behaved and performed?
We will never know the answers to these questions because the culture here is such that these things are not discussed publicly.
It was simpler in the earlier years when the MRT was run by a statutory board which the minister could instruct and direct accordingly.
With the much more complex structure today, he can do so only indirectly through the LTA but this depends on the rules and regulations in place.
Indeed, differences between the LTA and the SMRT became public during the Committee of Inquiry hearings in 2012 to establish the cause of the breakdowns that occurred the year before.
They disagreed over the quality of maintenance carried out by SMRT and whether it had led to the trains breaking down.
We also do not know how much Mr Lui agreed with the present arrangement where train services are run by listed companies, a system he inherited from his predecessors, though he was quick to dismiss talk last week that he had a problem with it.
Ministers here abide by the principle of collective Cabinet responsibility, which means we may never know.
Although individual ministers are responsible for their own areas of work, once the Cabinet makes its decision - and it could be one the minister disagrees with - he has to publicly defend it.
If he cannot do so because his conscience will not allow it or the disagreement is irreconcilable, the only recourse is to resign.
It will be interesting to see who the next transport minister is and what changes he makes which will enhance his ability to act.
But the ramifications of Mr Lui's decision also go well beyond transport.
More critically, it concerns the PAP's ability to attract people into its A team.
When Mr Lui first entered politics in 2006, he was following the footsteps of many of his seniors along a route unique to Singapore - government scholarship holder, then senior civil servant, and finally recruited by the PAP and headed for higher office.
The track record of those who made this journey was an impressive one: Goh Chok Tong, Lee Hsien Loong, Mah Bow Tan, Teo Chee Hean, Lim Hng Kiang, George Yeo, among others.
All served several terms and, together, they formed the scholar-minister model of political renewal.
None was a natural politician in the usual sense of the word - they didn't join the PAP on their own. They were asked to leave their civil service or military careers to join the ruling party.
But they were tutored and worked during a period when the politics was completely dominated by the PAP, the media was all mainstream, the Internet had not been invented, and the founding Prime Minister Lee Kuan Yew was around to provide the tutelage.
By 2006, when Mr Lui won his electoral seat, all these factors that had shaped the politics of his predecessors had already begun to change. He was a product of an old era but entering a new one where the political battleground would change dramatically.
As Singapore transits into a more competitive political landscape, the question is whether this model can produce the same results.
Will the greater demands and uncertain political career result in fewer people of ability being interested in the job?
Why subject yourself and your family to such intense public scrutiny and criticism?
Many people worry that this is the most serious consequence of the new normal, one which will ultimately affect the quality of political leadership in Singapore.
And even if some do enter politics, as Mr Lui did, will they be able to cope? Ask Mr Lui.
In the interview with Lianhe Zaobao, he said tellingly:
"In transport, I guess in most ministries... it is all consuming - in time, energy and focus.
"Because every (transport) delay, every (train) withdrawal comes to me. So I know when (delays are) on the uptrend because I can monitor it from my phone. So it won't be buzzing after this."
To be fair, he is the only one among his Cabinet colleagues - some of whom are younger and have as challenging portfolios - to have decided to leave.
Of course, you could argue that that's politics, and any party that wants to win elections has to accept this new situation or face the consequences.
Whoever it selects, no matter how bright, will have to cope and succeed in this new environment.
For the PAP, or any party with aspirations to run the country, this challenge is far more serious than any transport problem.