What is the main difference between white nationalists and citizenists?

Steve Sailer:

The white nationalists want to draw the line within America, around whites only.

And the citizenists want to draw the line at the border.

The problem is that "citizenists" like Sailer ignore the ongoing social problems created by past immigration into the United States. Securing our borders will definitely help protect us from the criminal activities of future illegal immigransts but what about those who have already migrated to the United States illegally and are currently engaged in violent crimes?