The Bottom Line:
The role of the Constitution: to restrain Government from acting beyond it'd defined role in the constitution to ensure individual liberty
The role of the Government: to protect sovereignty and liberty of the nation, that's it, nothing about welfare nationally or internationally.
Why? Cause long as you have freedom over your property and life, you may not have the life you want or you may have more than others, but you'll have the freedom to decide where you end up even if the path there isn't the same or as easy for everyone, at least it exists.