Well, the very opposite of that happened in the UK regarding the Brexit referendum:

"More than 50 per cent of the population growth in Lincolnshire in the last decade has been caused by immigration. Across the county, population growth has been 57,999, with 30,568 due to immigration - a total of 52.7 per cent."

https://www.lincolnshirelive.co.uk/news/local-news/new-figur...

"More than three quarters of the people of Boston, in the county of Lincolnshire in the East Midlands of England, voted to leave the EU. According to the most recent U.K. census in 2011, Boston also has the highest proportion of eastern European immigrants of anywhere in the U.K., after an influx of EU workers to the area’s agricultural sector, earning it the label of Britain’s “most divided town.” Between 2004 and 2014, the town’s migrant population grew by 460%, and the proportion of residents of the Borough of Boston born in EU accession countries such as Lithuania, Poland and Latvia, stands at around 12%."

https://www.cnbc.com/2019/11/28/in-boston-britains-most-pro-...

> The question we should ask is whether this is rational or not.

To vote a particular way in the hope of change? Why wouldn't that be rational?

And plenty of locals will go elsewhere too. I for one. The morons that effected Brexit should be enough of an example that any other EU country that wants to go the same route has been amply warned about what that will do your country. It's amazing that so many people are utterly blind but then again, live long enough and nothing really surprises you any more.