The "stimulus" was supposed to fix all that. Infrastructure was one of the bell-cows that got it sold. All we had to do was pass it to see that nothing but crony payoffs was in it. And as admitted much later, nothing "shovel ready" at all.
The rest of your post about illegal immigration - sanguine. The one and only thing we can do to maybe put a dent in it is for the economy to completely fail, or I dunno, how about streamlining the process for becoming legal, down to something reasonable like one year instead of the current seven-plus?
Talk of a wall is populist crap. More scary is the talk of cattle rail cars and such you can elicit from these morons if you give them that much conversational rope. Yes, they actually spew that having no idea at all where that puts them historically.
In superpunk's defense, I'll say what he should have said - most of the "national debt" is monies we owe ourselves, internally - it's a accounting thing - and it is completely unrelated and is separate from, the budget deficit.