I wrote a short text for the European Politics and Policy (EUROPP) blog on the link between immigration presence and voting for Vox, a relatively young radical right party, in the Spanish region of Andalusia. Full text is here, see also this post from 2015 about a similar link with Euroscepticism in the UK. The most important graph is below. Here is an excerpt:
To sum up, the available empirical evidence suggests that the relative size of the non-Western foreign-born population at the municipal level is positively, and rather strongly, related to the share of votes cast for Vox, the first Spanish radical right party to get in parliament since the end of Franco’s regime. Immigration might be responsible to a considerable extent for the resurgence of the radical right in Andalusia.