Defining white nationalism

The NY Times explains:

A question has been posed in a puzzled whisper in many of the nation’s living rooms and newsrooms ever since Donald J. Trump’s triumph in this month’s presidential election: What, exactly, is white nationalism? ...

Professor Kaufmann says the terms are not synonyms: White supremacy is based on a racist belief that white people are innately superior to people of other races; white nationalism is about maintaining political and economic dominance, not just a numerical majority or cultural hegemony.

For a long time, he said, white nationalism was less an ideology than the default presumption of American life. Until quite recently, white Americans could easily see the nation as essentially an extension of their own ethnic group.

But the country’s changing demographics, the civil rights movement and a push for multiculturalism in many quarters mean that white Americans are now confronting the prospect of a nation that is no longer built solely around their own identity.

So white nationalism is just the "default presumption" from a few years ago? If so, did we have some vote or collective decision to change it?

Maybe some of these ppl have some sinister beliefs, but the NY Times appears to use the term to include those who have little interest in race, but do not want to flood the USA with Third World immigrants and Islamic terrorists.