I live in a country (Austria) with at this point more than 20 years of a sort of digital ID. I’m really not quite sure how something as simple as authenticating as a citizen to access governmental services has become so controversial.
HN is typically more coming from a libertarian-anti-tracking bent but the larger popular US opposition to standardized federal IDs is rooted in "mark of the beast" stuff.
The premillenial dispensationalism theory is widespread in southern evangelical churches in the US, with big sales of associated media.
The association is "verse says a mark will be required and a number of the beast is mentioned" -> "these are numbers assigned by the government required for commerce" -> "this is the mark." The language of the apocalopytic verses is flowery enough that people pick and choose which parts they take literally, so for a while it wasn't seen as necessarily an injection (or you could also believe that eventually you'd have to get a SSN tattoo, say).
https://www.forbes.com/sites/peterjreilly/2014/07/16/social-...
https://www.faithfamilyfit.org/post/is-the-real-id-act-a-gat...
Easy to google for more, from varying levels of fringy-looking websites, but the "numerical ID == mark of the beast" fear is common evangelical American doctrine of the same source that saw these books sell 65 million copies: https://en.wikipedia.org/wiki/Left_Behind - they went digital with an injected chip, which is one of the things the Covid-19 vaccine sparked echoes of