Newly-ennobled Labour peer Shami Chakrabarti chooses to send her son to a selective fee-paying school and the air is immediately scented with confected media outrage at this alleged 'hypocrisy.'
It isn't. She has never voiced any public criticism of private education to be hypocritical about, and the fact that fee-paying exists is a distraction to far bigger questions about how we ensure a decent education for most children.
The new prime minister, Theresa May, has made allowing new grammar schools a signature policy. It may even dissuade more parents from paying the fees demanded by private schools. But the difficulty with grammars is that it won't be parents doing the choosing.
This is a problem. Selection generally works well for anyone selected, less satisfactorily for those left behind, which was one of the reasons grammar schools began to be phased out in 1965.
Mrs May hopes to combat this by obliging any new ones to build a 'high quality, non-selective free school' as well. There will also be obligations on private schools keen to keep their much-cherished, if curiously earned, charitable status to mentor state schools. But it is hard not to be apprehensive.
It can also be hard to get a grip of what is at stake. The debate about selective state schools is always one shot through with instinctive prejudices. Although Margaret Thatcher once described them as "a unique and irreplaceable educational ladder for the bright children of poor parents," grammars declined most on her watch as Education Secretary.
The discussion about their value will be fraught as it ever was: Between those who see grammars as bastions of good behaviour and high education standards, and those who see them as divisive and another way for the middle classes to manipulate their way into an excellent, free state service denied to others.
The truth may be somewhere between these two positions. It is certainly reasonable to start with the assumption that what they were and what they have become is different, as Mrs May has noticed.
They do provide, generally, all that they ever did in terms of experiences and high academic standards. But they do so to an ever shrinking pool; and are lifted and enabled by those lucky enough to live nearby, often in areas where the poor have been edited out by rising house prices that may themselves be a consequence of the school.
It is certainly quite striking that only 2.6 per cent of grammar school pupils are eligible for free school meals, compared with 14.9 per cent across secondary education as a whole.
But there is also no denying that grammar schools are widely supported, and this cannot be ignored. Politicians need to listen to their electorate, especially to people outside of London who may not feel included in evidence of rising education standards.
For example, Hampshire has a population of 1.32 million and 13 secondary schools classified as 'outstanding' by the schools' regulator. The central London borough of Westminster, by contrast, has a population of just 226,000, but eight 'outstanding' secondaries. It is just no good telling the rest of the country that standards in the state system are rising if they aren't much where they live.
But we must hold the Prime Minister to her promise of no return to that past when grammars creamed off the best pupils and staff, leaving an underperforming rump for everyone else.
There is also a less politically-charged alternative staring Government in the face. We now have free schools and academies managing to raise standards without resorting to academic selection.
These might be a better model. They offer academic streaming on a subject-by-subject basis, but without creaming off the most intelligent pupils into separate institutions. It would avoid denying both the highly able and their peers the wide and rich social benefits that come from integrating people from different backgrounds and uniting them around common hopes, expectations and opportunities.