We watched it play out in England, with Brexit. Right had be screaming about immigrants, from Eastern Europe, taking jobs. This whole rhetoric eventually lead to the fiasco that was Brexit.
After Brexit, the farmers (who mostly voted for Brexit) found they couldn't find the staff to pick fields. It turns out that the English unemployed won't do the back breaking work for a pittance. The food literally rotted in the fields. We also had a shortage of truck drivers. A lot of our truckers were Eastern European, and saw which way the wind was blowing. They decided to work more in mainland Europe.
In the end, it wasn't immigrants taking our jobs. It was immigrants doing jobs we didn't want to do. Or filling in skill holes our workforce couldn't cover.
Because you guys don't pay enough and treat the workers well enough. Thats the plain of it. And yall kept importing cheap labor well after brexit, still do.
The itinerant workers decided they didn't want to deal with the issues, so far less are available.
The system couldn't adapt to the change fast enough (food price adjustments etc).
The people who took most advantage of the situation were also the ones bitching about the "immigrants stealing our jobs!". They lost out particularly hard when those same immigrants said "ok, we'll go elsewhere".