Originally Posted by
catocony
That's correct. You don't actually need a US Passport to re-enter the US. You'll be delayed, but once they verify your identity through database search, you're good to go. The problem is getting on the plane from wherever back to the US.
100% correct. And of course you can enter by land from Mexico or Canada. In the old days you did not even need ID though often they would ask for a drivers license.