When the first presidential election was held in 1993, enabled by changes to the law in the preceding years, concerns were raised about the stringent qualifications required for candidates.
Spelt out in the Constitution was that aspirants must have held, for at least three years, key positions in the public or private sectors. Members of Parliament had wondered then if this would narrow the field too much.
Twenty-three years and three elected presidents later, the same concern has again cropped up as a Constitutional Commission considers if the eligibility criteria should be updated.
At the four public hearings held on the review, opinions were split about doing so. But there was a consensus among both camps - that whatever changes made should not lead to too few people qualifying.
Article 19 of the Constitution lists the various qualifications a president must have.
It states, among other things, that a candidate must be a person of integrity, good character and reputation.
If he is from the public sector, he must also have served in key positions, such as as a minister, chief justice or permanent secretary.
And if he is from the private sector, he must have held, for at least three years, the post of chairman or chief executive officer at a company with a paid-up capital of at least $100 million.
Taken together, said Prime Minister Lee Hsien Loong in January when calling for the review, the eligibility criteria are meant as a proxy for determining if a candidate has the experience and competence required for the job.
The president's tasks include protecting Singapore's national reserves and the integrity of the public service, and acting as a check on the Government in its investigating and detaining of people.
The criteria, the Government had said in 1990, amounted to a job screening of sorts. Regular job applicants are subject to similar screening, so what more a person aiming for the highest office in the land, it said.
And as the complexities of the job have increased, the criteria are due for an update.
Over the years, the national reserves that the president safeguards have grown, said PM Lee. Central Provident Fund savings alone, which make up a part of the reserves, stood at $275 billion last year. In 1990, they were $41 billion.
But a small number of those who spoke at the hearing begged to differ.
They argued that it is political acumen, and not financial judgment, that a president must possess to do his job well, as he is merely empowered to say yes or no to items like the Government's Budget and use of the national reserves.
In such "binary decisions", said constitutional expert Kevin Tan, what matters more is whether a person has the stomach to go against the whole government machinery.
Qualifications that focus on measuring a person's financial knowledge thus do not have to be set so high, he said.
Some others, like rights group Maruah and the Association of Women for Action and Research, felt such criteria should be dropped altogether.
THE $100 MILLION QUESTION
Those in favour of tightening private-sector requirements suggested raising the company paid-up capital threshold to ensure that aspiring candidates have the right experience.
If they have run large and complex companies, they would likely be more adept at dealing with complex financial decisions, they said.
Most did not suggest a specific threshold, but several pegged it at $500 million.
Lawyer Ranvir Kumar Singh arrived at the number using as a benchmark, Singtel, which he deemed a large enough company. The telco's paid-up capital value had gone up five times since the elected presidency was implemented in 1991, he said.
Chief Justice Sundaresh Menon said the higher threshold would capture the top 0.2 per cent of firms here - the same proportion captured in 1991, when the threshold of $100 million was set.
Executive chairman of listed Raffles Medical Group Loo Choon Yong suggested it should be $500 million in shareholders' funds or net tangible assets instead, since these measurements more accurately reflect a company's actual financial strength.
He also suggested that only those running publicly listed companies should be considered, as these are subject to scrutiny by regulators and the public.
However, others said that whether a candidate has the right experience cannot be determined just by looking at the size of the companies he has run.
To get at the substance of his corporate role, factors such as annual revenue and number of employees should also be taken into account, said former Cabinet minister S. Dhanabalan, who is a member of the Council of Presidential Advisers and the Presidential Council for Minority Rights.
When the experience was acquired also counts, said Institute of Policy Studies (IPS) deputy director of research Gillian Koh and IPS researcher Tan Min-Wei.
To qualify, candidates should have held their posts within the past 10 years, to ensure that their skills, knowledge and experience are still relevant, they said.
Singapore Management University law don Eugene Tan and Eurasian Association president Benett Theseira warned against shrinking the pool of eligible candidates too much, especially for minority race groups.
Commission members noted that the pool had grown since the 1990s.
If a presidential election were called now, the head honchos of at least 2,145 firms could potentially qualify to run. During the first presidential election in 1993, there were only about 100 such firms which met the $100 million threshold. (These CEOs and chairmen would of course have to pass muster in other ways, too).
So just how big should the pool be?
None at the hearing had a ready answer when asked by Chief Justice Menon, who chairs the commission.
If the threshold were raised to a paid-up capital of $500 million, 503 out of a total of 294,700 companies here would be captured, statistics from the Accounting and Corporate Regulatory Authority show.
How this would affect minority-race candidates, though, is uncertain. But if Singapore's racial make-up is any indication - Chinese made up 76.2 per cent, Malays 15 per cent, Indians 7.4 per cent and other races 1.4 per cent of the population in June last year - there could be more than 100 potential candidates from the minority races.
But while is it important to ensure that there are sufficient numbers of suitable candidates, the size of the pool should not be the determining factor in setting the eligibility criteria, said Chief Justice Menon.
"You can't set the criteria by looking at the individuals and say I think at this level we will have so many suitable candidates...
"If the view is that the criteria should be updated, then surely we shouldn't resist doing so for the sake of minorities," he said.
He added that the paramount consideration for whatever eligibility criteria should be to ensure that candidates have the experience and competence needed to fulfil the president's duties.
To satisfy these requirements, substituting the fixed paid-up threshold with a mathematical formula to calculate the threshold may be the way to go. The absolute number can then be worked out each time a presidential election is due.
This would help the eligibility criteria keep pace with the scale and complexity of the job, said Dr Koh who suggested it.
It would perhaps also satisfy an aim of the commission: to draft a constitutional provision that can withstand the test of time.