The launch of the Climate Change Commission's report was a polite affair. Either everyone's on aboard with the biggest transformation of the economy in history, or criticising it feels risky.
A family member who is an NHS nurse in Wales is worried about the cost of lockdown there for her working-class friends, stuck in tiny flats in tower blocks and losing their jobs.
Her brother now thinks she's a right-wing religious zealot. She told me, "Politics is splitting our family apart. Why has it got so personal?"
One reason is that politics is in a transition. Political parties are dividing over symbols as often as substance. When a policy is a symbol of our identity, criticism of the policy is criticism of us personally.
For much of the twentieth century, the best predictor of a person's politics was their parents' preference. Our grandparents were divided by a tribe for working people, and a tribe for the establishment. Rights of workers, safety nets without morality tests, and "one person is as good as another", versus respect for a natural social order in which everyone knows their place.
Political science observed those party affiliations breaking down. A theory took hold that if you didn't vote the same way as your parents, it was because of social mobility. The poor were getting richer, and the workers' parties embrace of progressive change had won over the elites.
But it's looking more like the parties, not the voters, that are changing.
Social mobility is stalled. Rising inequality means less chance for the daughter of a nurse to enjoy the same "luck" as the son of a hedge fund manager.
Tribal affiliation is more intense. In the United States, a recent experiment at Yale University asked students to rate two welfare policies. One was generous, the other not. As expected, Democratic Party supporters liked the generous policy, Republicans the less generous.
Then, when researchers presented the generous policy with quotes from Republicans stating, "this strikes the right balance between personal responsibility and looking after the vulnerable", support from Republican students doubled. When high-profile Democratic leaders were seen to endorse the less generous welfare policy, support from Democratic students increased.
The policies didn't change. Party endorsement beat policy content.
When divisions are less about social class, and more about identity and symbols, then activists support their tribe because of what it says about who they are — not because of substance.
Tribes signal identity by choosing a pick-up or a Prius. Do they talk more about God or climate change? Do they put gender pronouns in their emails?
Parties of the right, globally, have cynically used symbols to signal identity and create division. They use national symbols to signal to some who feel ignored - and to exclude others. Refugees, immigrants, foreigners. Even locals who are different.
The ultimate tribal politician is Donald Trump. Being on his side was all that mattered. The only fair election was one he won, and the only good person was one who was loyal.
Around the world, political representatives of working-class parties are more likely to have university educations. It's a good thing to be educated, but a degree is also a proxy for being middle class.
Those who are not in the educated middle class and not socially mobile need representation as well. One lockdown meme in Britain has been the social divide between people who shower before work and those who shower after work.
We used to mix more with people who were different from us. You went to church or played sports with people with opposing political views.
In the 1960s, only 5 per cent of Republicans and 4 per cent of Democrats said they would care if their child married someone with opposing political views. Today, pollsters YouGov have found nearly 50 per cent of Republicans and 33 per cent of Democrats would care very much.
Kiwis are not as divided as Americans. Nationalist parties, like those seen in Europe, are not thriving here.
But we have the ingredients.
Inequality is sharply increasing with house prices rising and a tax system aimed at incomes, not wealth. Researcher Max Rashbrook has shown that the top 10 per cent in New Zealand now own $800 billion in wealth, while the bottom 10 per cent owe $13 billion between them.
Our politics are often about "being good" instead of "doing good". Last week we saw the tribes divide - albeit politely - into pro-or anti-barbecues.
And yet when politics is truly about the personal, we have so much in common: getting kids through school. Having enough money to pay bills, buy a home, and retire. Having our health and time to spend with family and friends.
What we need now is the right kind of personal politics - a politics of this ordinary stuff.
• Josie Pagani is executive director of the Council for International Development.