You are getting onto VERY dangerous ground if you start using race to gerrymander elections.
BTW This aging populice world moving to the left theory has been around decades and rigourously debunked. You need large numbers of young people to push left, ie baby boomers.
A referendum for what?
We haven't had one to go into political union so we dont need one to leave. Any referendum should be about re-entry or remaining in as the automatic assumption should be is that we are leaving.