Of all of the policies Donald Trump has pinned his election hopes on, until this week the removal of fluoride from America's drinking water had not featured high on the list.

In the final days of campaigning, the former president might have preferred to demonstrate his strengths on immigration and the economy.

Instead, he has found himself discussing a possible reversal of the decades-old practice, hailed by some as one of the United State's greatest public health victories.

The plan is the brainchild of Robert F Kennedy Jr, the former independent presidential candidate, who is set to take a leading administration role if Trump is re-elected.

"It sounds OK to me," Trump said on Sunday. "You know, it's possible."

It was the latest example of Trump's campaign embracing the anti-vaccine campaigner, including courting him for a role overseeing the health portfolio.

Mr Kennedy dropped out of the presidential campaign in August to endorse Trump for the White House.

But owing to the late nature of his withdrawal, his name remains on the ballot in the heavily-contested swing states of Michigan and Wisconsin.

While support for Mr Kennedy is low in the key battleground states, it is sufficient that he could effectively rob Trump or Kamala Harris of victory.

Tapping into the concerns of Mr Kennedy's supporters and persuading them to cast their vote for him instead could provide Trump the boost he needs to get over the line.

Pollsters say these voters are generally anti-establishment and hold more unconventional views on health than the majority of people.

Mr Kennedy is a prominent critic of vaccines, and has claimed childhood immunisation can cause autism.

Last week, he said fluoride was "an industrial waste associated with arthritis, bone fractures, bone cancer, IQ loss, neurodevelopmental disorders, and thyroid disease".

A Trump-led White House would advise US water systems to remove the chemical on January 20, 2025 -- inauguration day -- he added.

The practice of putting small doses of fluoride into American water began in Grand Rapids, Michigan, in 1945.

In 1962, the US Public Health Service recommended adding small amounts to drinking water to strengthen teeth.

Almost 210 million people are on fluoridated water systems, according to the Centers for Disease Control and Prevention's latest estimates.

The American Dental Association said the move has reduced dental decay by at least 25 per cent.

But like with mass-vaccination, fluoridation of water has long been the subject of health concerns and conspiracy theories.

These claims have not always been unsubstantiated.

A US government report published earlier this year suggested consuming fluoride at twice the recommended amount is linked to lower IQ in children.

In the past, fluoridation has been linked to health conditions such as fluorosis - a build-up of the product in the teeth and bones - as well as bone cancer, impaired brain development and Down's syndrome.

America's practice of adding fluoride to drinking water is much more substantial than many of its Western allies, such as the UK, where only 10 per cent of Britons have the mineral added to their water supply.

Many European countries have also opted against or phased out artificially increasing fluoride levels in water supplies.

A 2003 study across 16 European nations found that "the vast majority of people opposed water fluoridation".

Mr Kennedy's concerns over fluoride in water come amid a growing sentiment in America that its citizens are consuming too many additives -- and it is not the only one of his policies that the Trump campaign seems open to.

In recent years there has been somewhat of an anti-establishment backlash against products such as processed food and drink, vaccines and heavily chemically-enhanced toiletries and cleaning products.

Mr Kennedy has said he wants to ban pesticides, seed oils and food additives.

JD Vance, Trump's running mate, seemed to echo some of these concerns when he spoke of the virtues of ditching processed foods like vegan meat substitutes on his recent appearance on Joe Rogan's podcast.

On the Joe Rogan Experience, Mr Vance also cast doubt over the safety of the Covid vaccine -- another key concern of Mr Kennedy.

If RFK Jr did end up in charge of health policy, it is likely to see a fundamental change to some of America's most prominent health institutions.

In the lead-up to the election, he has suggested overhauling regulators, whom he claims are "sock puppets" to the pharmaceutical industry and are making Americans less healthy.

Other proposals are more akin to those put forward by Ms Harris, like price-caps on drugs and crackdowns on processed foods.

Backing these seemingly fringe health issues might get Trump over the line and into the White House.

But they also might set the US on a path that is much more sceptical about traditional public health expertise.