so its only for those entering Canada now?!
If you believe they can eradicate it entirely and keep up these measures long term.
Regardless, do you actually believe we can implement or enforce such a draconian measure in the US (i am skeptical as to whether it's even constitutional) ?
Constitution can be amended (or tossed out). It's not the end all.
I don't think America can eradicate it at this point, it would take an extremely strict nationwide lockdown for 3-4 weeks, society wouldn't comply, and has weapons to rebel. The best hope is to slow it down to keep hospitals functioning and hope to advance testing/vaccine/medication, and it's likely most fo the world will remain closed to Americans in one way or another until significant progress is made with testing/vaccine/medication.