Allow me to invoke my psychic powers to tell you that the author of this article was inspired to write it based on the recent rise of Marine Le Pen in France and Geert Wilders in the Netherlands, among others. While it is entirely possible they will not be elected, they have a plausible chance of winning, and they fit the model of far-right white nationalists better than Donald Trump does.
If you think the welfare states are the cause of this, I have something to tell you about the complexities of multiculturalism, austerity measures, the actual dismantling of the welfare state, late capitalism and historically unprecedented inequaltiy, racism, etc.