I really doubt a President Trump would do much more than say Obama in reducing illegal border crossings. I do think some things Biden said early on stimulated it greatly.
The amnesty thing as noted is in our code (as well as international law, which really isn't a thing).
Most of what I hear politicians SAY I treat as guff, not reality, pandering to the base, which doesn't include me.
I also don't think Democrats want to limit LEGAL immigration, nor do some Republicans (Koch was mentioned).