For fellow Americans living in cities where ICE is active, many people, especially those of Hispanic descent, are already carrying around passports on their persons at all times because they're rightfully afraid of being forcibly disappeared or deported to some random South American country.
A passport card can be obtained for $30 from the Department of State. It is considered exactly equivalent to a passport within the US, but it's the size of a credit card. It is a valid travel document for land and sea travel within North America and the Caribbean. It also counts as a Real ID. The card is good for ten years.
Do not do this if you are transgender or have an X gender marker. They will cancel your passport and tell you to apply for a new one with your sex assigned at birth.
Apple has been trying to get states/governments to let them add their ID to Apple Wallet for years now. Only a handful of states have complied. I'm not sure if you can add a passport.
The most common misconception is that a cop will take your phone and have access to all your personal information plus they're in your phone. That's not how it's intended to work (but absolutely can regardless of whether your state supports digital ID). The intended use is much like paying for goods, they hold up a reader, you open Wallet and select your ID, tap your phone to their reader, and they can see all the relevant information. And it's encrypted and all that.
Of course, I'm talking about cops following procedure, not thugs working directly for Trump.