I didn't read this whole thread, but I'd imagine the reason they're doing this is has to do with taxes. There were probably some states that had relatively lax identification requirements to get a CDL previously, and there were foreigners getting CDLs under false or assumed identities, then going to work for companies as contractors. Then they'd get an IRS form 1099 showing they were paid tens of thousands of dollars, but no one would ever file taxes on it, and they were impossible to locate.
Just off the top of my head, many states standard ID requirements for a driver's license would accept a foreign birth certificate, and didn't previously require proof of citizenship(not sure this is still the case), so if CDL requirements just allowed a state ID in order to get a CDL, it wouldn't be difficult to obtain. I recall at least 1 state that, around 15 years ago was still issuing licenses that were just a paper card with a picture glued to it, then laminated. I don't know if/when all states changed to the newer hologram DL's.
