So would you predict a correlation between number of immigrants in a county/state/country and nativist electoral success? I don't think that is the case.
I get that immigration is a hotly debated culture war topic, but I am not convinced by the argument that immigration is the thing that is causing the culture war.
I'm not really talking about electoral results. I'm talking about the NYT articled I linked to, which measures "how right wing" a party is by looking at what's mentioned in the platform. But what's mentioned in party platforms is a product of what debates are happening in society. In places without much immigration, immigration isn't a focus of politics and won't warrant merit on party platforms, even if the members of the party would have strong nativist views if there was actually a significant amount of immigration.
For example, in the United States, "making English the official language" was a hot-button political issue for a long time (before even Republicans gave up on it). In France it wasn't, because nobody disagreed that French should be the official language (and it was). So if you read party platforms to gauge right-wing views, you might conclude that the French aren't right wing on this point, because party platforms don't mention it. But in reality, it's not mentioned because it's not something that's even up for debate.
It's not necessarily as nativist as you'd think, because « la francophonie » is more inclusive than those who can say « nos ancêtres les Gaulois » with a straight face.
I get that immigration is a hotly debated culture war topic, but I am not convinced by the argument that immigration is the thing that is causing the culture war.