"...the union of flight attendants, which is calling on the Department of Transportation, in coordination with the Department of Health and Human Services, to “end all leisure travel until the virus is contained”
What's the history of the DOT and DHHS coordinating together on orders of that magnitude? Would their combined authority alone be able to put forth something like this as an enforceable emergency order vs. a recommendation? How long would it take for a workable policy to be formulated and made effective? And as others have touched on, what would be required as proof of essential travel? Or would the burden be given to gate agents or flight crew to discern case by case, like denying boarding to drunk passengers? ("You can't fly today; you look inebriated. And you can't fly today; you look like you're headed to PHX for a golfing weekend.")
I'm asking from a place of complete ignorance on related policies and precedents. I'm curious how this might even work.