The pressing issue of this time is what is the path to cultural restoration, and you can't do a cultural restoration while you have massive amounts of immigration.

Why restoration, and not building something new and well-adapted to the knowledge and needs of the 21st century?

Because median intelligence has dipped and western culture no longer values the right fields. We're left with an unexplainable longing for a time that doesn't and never existed.
There was an idea that was Rome.
Few understand positive nihilism. To create something new we must reject the past.