The rise of white nationalism is the logical reaction against that movement. Aka therefore the culture and tradition associated with people of Caucasian background should be preserved and the best way to preserve it for people of different cultural background to live in their own communities instead of intermixing. Aka no immigration from countries with different culture
Once we accept that we should respect the traditions and culture of another society, the conservative counter-reaction of what about our traditions and culture is inevitable.
The only way to defeat white nationalism is for the left to say that nothing is sacred and treat every belief and values based on individual merits. Aka classical liberalism