I’ll digress that immigration was seemingly a big reason for Brexit winning support among many of those who voted Leave. At very least, I know quite a few Brexit voters who voted the way they did due to immigration concerns.
My grandad voted Leave, and he always told me that Brexit was the right move because “the UK is like a box, and freedom of movement is like somebody shoving stuff into the box incessantly until it won’t fit”. He has said that he would vote Leave again if another referendum was held.
My mum’s brother voted Leave, and I once heard him complaining about “all those foreigners coming in on their boats”…
I can tell that a distant relative of mine almost definitely voted Leave simply by some of the things they shared on Facebook. They shared a lot about foreigners, the need to get foreigners out, and basically a lot along the lines of “all those foreigners coming in, taking our jobs” and such. They also shared staunch admiration for the likes of Nigel Farage.