Well I have asked a few, they have experienced a past with far fewer brown faces in it, that seemed to be the major factor.
Oh yes, and I can just imagine the conversation.
"Excuse me, I'm doing a survey on older people and the EU for my GCSE course work. Can you spare me a minute to answer a few questions?"
"Oh, I suppose so - OK."
"Thank you. First question: in the 2016 Referendum did you vote to leave the European Union?"
"Yes."
Thank you, and finally: when you were young were there many black or brown kids in your school?"
"No. Very few, actually."
"Thank you, that's all I need. Thank you very much for your help."
And on such facts do so many young remainers come to these irrefutable conclusions:-
1). All leavers are racists;
2). All older people are racists - and, probably in many cases -
3). People who don't agree with us are racist.