I doubt many are. Too many hoops you have to pass through to be an interstate bus driver.
That being said...with this announcement, at least in my mind, Greyhound is no longer a safe way of transport for any Normal, Deplorable, or conservative. They are now destined for bankruptcy unless they change their mind, and swiftly.
The hound should have been the first level of security, profiling and scrutinizing their own passengers.
I'm surprised we haven't had a "palestinian" blow up a bus.