Why does Mezcal in the USA have a higher minimum ABV than Mexico?

Mexican regulations require an agave spirit to fall between 35% and 55% alcohol by volume (ABV) to qualify for certification as mezcal. But in the USA, the TTB requires that same spirit to be a minimum of 40% ABV to qualify as mezcal. Why? Well, who knows? Not us! But that doesn’t stop us from blindly speculating! It’s another meandering episode of Agave Road Trip!