Prejudice from people like Copper is a horrible thing 
A visceral dislike of the ECJ just because it is the ECJ
and a dogmatic determination to accept any other jurisdiction, even where the UK would have less influence 
And a visceral determination to blame all schooling woes on immigrants rather than lack of funding (especially since on balance, EU immigrants contribute more to public coffers than they take out - so they are the ones being exploited)
For balance: 60% of the pupils at ds' old state primary school spoke English as an Additional Language (EAL). It was still (or rather, because of that) a brilliant school, an exemplar of best practice at dealing with EAL.
That proportion is unlikely to change with Brexit a) because we are in Scotland and need (and welcome) more immigration (although have no say over immigration policy
) and b) most of those EAL speakers are from the Punjab and speak Urdu as their first language.
At his old state secondary school there are apparently 55 languages spoken
. It still manages to get excellent results, thanks to a fantastic ethos (which celebrates the diversity) and a good management team and, of course, great teachers
. And more importantly, it turns out well rounded individuals, well equipped to cope with life after school
(Very low drop out rate at Uni as they are taught how to be disciplined and organised, rather than spoon fed, unlike schools in a neighbouring LA which theoretically has better exam results whose pupils have a very high drop out rate when they have to think for themselves do their own work
).
I am glad to live in a multi-ethnic city. 
Oh - and we voted 70% Remain. I don't think that that is a coincidence 