Subject: Acceptable to ICE
Omar's son was born in the US and he showed the ICE agents his passport ID and was let go, Ilhan Omar said. She said her son always carried his passport.

https://timesofindia.indiatime...

So if you look like a Somalian, you should carry your passport. Third time I've read ICE accepts passports for proof of citizenship. They do seem to have a facial recognition database, but I've never heard of them using that in the field.