More than twenty years ago, a film imagined something quite simple.

One morning, California wakes up and the Mexicans have disappeared.

They have not gone on holiday. They are not protesting. They are simply no longer there.

At first there is confusion. Then the small problems begin. Workers are missing. Some crops are left unpicked. Some businesses cannot operate. Little by little, what first seemed like an absence begins to look like a general breakdown.

The film was called A Day Without a Mexican.

I thought of it a few days ago after seeing an election billboard featuring Winston Peters.

It did not say much. It did not need to.

NEW ZEALANDERS FIRST.

I found myself thinking less about the word first than about the two words before it.

New Zealanders.

Who, exactly, fits inside those words?

New Zealand, of course, has every right to debate its immigration policy. It has the right to decide how many people it welcomes, what the requirements should be for residence or citizenship, and under what conditions someone can access certain state benefits.

Debating immigration does not automatically make anyone xenophobic.

What interests me is something else.

I am interested in what happens when different debates begin, little by little, to point towards the same person.

The immigrant.

New Zealand First is proposing that only citizens should be able to vote, ending a right currently held by residents who meet the electoral requirements. It has also announced that, from 2029, it wants NZ Superannuation to be available only to citizens.

This comes as New Zealand is already gradually increasing the number of years a person must have lived in the country to qualify for NZ Super. For those born from July 1977 onwards, the requirement will reach twenty years of residence from the age of 20, including at least five years after the age of 50.

Each of these decisions can be debated separately. There will be economic, demographic and political arguments for doing so.

But sometimes it is worth stepping back from individual policies and looking at the picture they begin to form together.

Because then the conversation is no longer only about who can enter New Zealand.

It also becomes a conversation about how much someone who is already here belongs to New Zealand.

And we are talking about a lot of people.

The 2023 Census showed that 28.8 per cent of people who usually live in New Zealand were born overseas. Almost three in every ten people.

The economic numbers tell us something too. A Treasury analytical note calculated that, in the year to March 2024, people born overseas represented about 32 per cent of the population but paid 38 per cent of individual tax on market income.

But perhaps stopping at those numbers would be to make the very mistake I am trying to avoid.

Because a person's belonging to a country cannot be measured only by what they produce.

So let us try the experiment from that old film.

Imagine that tomorrow morning we wake up and New Zealand's immigrants have disappeared.

All of them.

Yes, workers would be missing from Queenstown's hotels. From the orchards and farms. From hospitals. From Auckland's kitchens, Christchurch's building sites, and the tourism seasons of Rotorua, Taupō and Te Anau.

But other things would disappear too, things that are much harder to measure.

Languages we hear every day on our streets. Restaurants that did not exist twenty years ago. Teachers, artists, doctors, scientists, athletes and small-business owners. Entire families. Friendships. Different ways of celebrating, cooking, raising children and seeing the world.

There would be children waiting outside a school for parents who would never arrive. Empty places in sports teams. Missing neighbours. Businesses closed not simply because there was no one to work in them, but because the person who created them had disappeared.

And something stranger still.

Many children and young people who have probably never thought of themselves as immigrants would disappear too, even if their parents are. Children who learned English here, who know these mountains and beaches as the landscape of their childhood and who, when someone asks where they are from, simply answer New Zealand.

Perhaps then we would understand that immigration was never only about labour.

It has also been one of the ways contemporary New Zealand came to look like itself.

New Zealand is not about to expel its immigrants. It would be irresponsible to suggest otherwise. Nor is every restriction on immigration necessarily an expression of hostility towards them.

But political climates rarely appear overnight.

They take shape.

In a phrase. On a billboard. In an apparently small distinction between citizen and resident.

In the repetition of an idea that, after we hear it often enough, begins to feel natural.

New Zealanders first.

There is something seductive about those words. Who could object to a country looking after its own people?

The problem appears when we try to finish the sentence.

If some people are first, who comes second?

The person who has lived here for twenty years but never applied for citizenship?

Someone who pays taxes, bought a home and raised their children here?

The permanent resident?

The worker who arrived five years ago?

At what point does someone stop being a person who came to New Zealand and simply become part of New Zealand?

Queenstown knows that question well. But it is not a Queenstown question.

It is a question for Auckland, Christchurch, Rotorua, Wellington, Taupō, Te Anau, and for the small agricultural and tourism communities where people who arrived from other countries long ago stopped being an immigration statistic and became the neighbour, the nurse, the builder, the teacher, the café owner.

Perhaps, then, the most important question is not how many immigrants New Zealand needs.

There is another one that interests me more.

What New Zealand would be left if tomorrow they all disappeared?

Because I suspect we would spend much of that first day discovering something we had preferred not to see.

That while we were debating whether they belonged to New Zealand, New Zealand had already become, in some small way, theirs too.