Diaspora, while benefiting from free movement and pluralusm, often feel like they’re losing their identity. In turn, they seek to symbolically reassert this identity by remote-voting for the most far-right maniac they can find. The fact that such a maniac would never have let them in, and will ruin the country, doesn’t bother them as they don’t live there anymore.
Thet benefit by feeling closer to (what they imagine is) their culture. We’re talking about people who left for some quick cash and ended up spending 30, 40 years there. They have a daughter that’s born there, grew up there, and never lived outside of there, and they worry she’ll be sad when she has to break up with her boyfriend “when we all move back home”. They feel like they’re separated from their nation because they are, and psychologically deny this by voting for someone so rabidly and loudly nationalist they can hear him all the way in Frankfurt.
It’s similar to folks from, idk, Boston, who will occasionally vacation in Ireland and conclude “they’re not Irish at all over there, they don’t even paint rivers green on St. Patty’s!”