Comment by ChrisMarshallNY
4 hours ago
I suspect that the main reason is that politicians rely on the same mechanisms as robocallers and spammers, so they don't want to restrict it.
Sometimes, I get robocalls from local PACs, and they get automatically flagged as scams, because the dialer companies that the politicians use, are ones that also run outright scam campaigns, and get blacklisted.
> they get automatically flagged as scams, because the dialer companies that the politicians use
If it were possible to reliably determine the source of a call in the US phone network, spam wouldn't be an issue!
Theoretically, STIR/SHAKEN should enable that; practically, there are too many gaps to enforce it (importantly, it does not travel across TDM, i.e. non-VoIP, paths), so spammers still get away with it.