Problem with that is illustrated by the data It Will Never Work posted up, either here or on another thread, which showed a marked rise in reported hate crime from the moment the brexit referendum campaigns started. There is a very distinct 'before' and 'after' pattern to the levels.
So the conditions that led to the leave vote certainly included 'more racism', from years earlier, a concerted anti-immigrant campaign on various fronts - the Express had been at it relentlessly for 20 years. But the campaign and the result of the vote also had a direct effect. They unleashed and empowered various extremely nasty political forces, and led to the situation where Boris Johnson won an election talking just like Nigel Farage, openly referencing immigrants and the way they are taking over.