Just returned from voting in LA, CA.
There was an unattended registered voter list posted at the door to the polling place. I stopped and looked at the list to see which voter I would 'be' once I walked on in.
When I spoke the name I had decided to use, I was not asked for any ID or proof (or suggestion) of who I am. I signed a squiggle next to the name on the list, and was handed my ballot.
The place was pretty much deserted, only 1 person in line ahead of me. Voters were outnumbered by the workers present.
FYI, the name I picked from the list was my own; however it obviously did not need to be - I could have voted as 'anyone'.