Just to clarify, current use of marijuana is a disqualification for a security clearance. Past use of marijuana is not a disqualifier. When I was a younger man I used marijuana, mushrooms, LSD, cocaine and MDMA. Several of them very frequently. I disclosed all of this prior use and was able to get multiple security clearances through the years.
I no longer have nor will in the future have a security clearance so I now enjoy my legal weed.
The entire theme of this thread is "nothing stops the same from happening tomorrow". One president can order the DEA to reschedule it, and then the next can undo that work just as easily. We need a law, not an executive fiat. Most of the country is in favor of legalization, including most republican voters, so you'd think it would be easy to get the house on board, had it not been co-opted by right-wing extremists.
With that said, they aren’t proposing to grant federal legality to the state-legal recreational marijuana market. They are planning to reclassify it from Schedule I (no recognized medical use) to Schedule III (the same category as anabolic steroids or testosterone and less restricted than Adderall), so the proposed federally legal way to get it would need a prescription and dispensing by a pharmacy or doctor.