>Does this apply to illegal aliens?

How could it? Undocumented people are undocumented. The harder / longer the process the more likely people are just find ways to forgo engaging with it. Especially if it looks like positive outcome is unlikely.

Would need to see a citation on the rest of you've said as it sounds a little like right wing talking point.

Seems a bit rich the descendants of many migrants are pulling up the ladder.