So much to say about this frightening few days.
One is that, in this country at least, people generally seem to confuse or conflate EEA migration with non-EEA immigration. That's why is comes down to a question of racism and xenophobia and their various (shady) shades.
Another is that they don't undertstand immigration, its variety of categories or the reasons for it. Many of which are sound, and important. And that does reduce to racism, not of a virulent kind, but of a miasmic kind. This has infected the "Baby Boomer" generation as much as their elders.
Another thing is that the actual problem, which is the combination of ghettoisation and immigration, which is an argument about integration not immigration, is a minority problem which is massively inflated in the media and poisons the minds and opinions of large numbers of people who do not live in the small number of large cities that have to deal with this problem (or prefer to ignore or normalise it), and therefore does not effect them at all. In the ghettos themselves (I work in one, Butetown in Cardiff Bay, formerly 'Tiger Bay') the assimilation argument happens within the communities and quite often between generations. This is a more interesting and aposite place for it to happen, and it is the younger generations who are the more radical, and recent immigrants, from say Somalia and Yemen, are dealing with some of the same shit they dealt with where they came from.
Another is that the promotion of "multiculturalism" in such contexts (Middle or Little England or North Wales, say) where they have no relevance has had the opposite effect than intended, and has mestastised with a distorted political argument. So people are voting against foreigners in places where foreigners don't exist or do and aren't a problem.
Another is jobs, and that is an argument about the expectations of school-leavers and graduates and the nature of the work actually available in service economies, among many other more complex issues.
In terms of these elections, they are different from when, say, the National Front got a councillor in the Isle of Dogs in 1993 or Le Pen had to be trounced by Chirac in 2002 to save France from fascism because:
1) This vote could well be replicated in general elections across Europe.
2) The number of countries in which people voted for these parties at the same time, which suggests a continent-wide pattern.
3) The fact that people are registering their protest votes for far-right parties and not (in general) far-left or socialist parties, and therefore the thrust is reactionary, racist, isolationist.
4) The fact that many of these parties are pro-Putin and for the tenor and tactics of the Russian nationalist strain of his extended political milieu, which I think many people in Europe do currently admire (anti-EU, anti-NATO, anti-American, anti-gay, pro-narrow national interest, etc.)
Some random panic-striken thoughts, apologies for any mistakes or distortions.