[mrweasel]

Also visas expire, so why not simply implement better checks for new visas. Most of the 55M visas are probably fine, so you have to spend an exorbitant amount of resource on finding very few issues. It's much cheaper to add additional check to new visa applications.

55M is also just a crazy amount of visas for a country with 350M citizens. Especially given that I'd guess that a large amount of people travel to the US on a visa waive program.