• The migration crisis is over and everyone is rich and prosperous again
• Non-fascist parties learn how to talk about these things in ways that make sense to people
• People get a clue and realise that the far-right isn't good for anything or anyone

I don't know if any of them are all that likely, but I guess there are other possibilities as well.

you mean the migration 'crisis' and collapse in '"living" standards' which were brought on by US-EU neoliberalism driving down the standard of living in other parts of the world before coming home to roost?

there are certainly ways of reversing direction, but people in the core would sooner choose literal fascism before giving up their imperial lifestyle. they use the IMF to politically terraform 'underdeveloped nations' and export their own harms so they can say they're 'meeting climate goals', and then complain about all the emissions and migrants coming from those countries which are ravaged to supply their hyperconsumption. the same migrants which predominantly staff their service, medical and technology sectors to prop up their precious treats and their oh-so superior 'knowledge economies'.

voting for fascism is the individualistic choice which lets them keep their treats and means they don't need to interact with their neighbours or advocate for real change. it's easier to blame the victims of their actions than to cut the DARVO shit and accept responsibility.