Yeah, it's inconsistent between states. I'm in VA and an ID is required. Despite being a bleeding heart liberal, I'm ok with that safe-guard (despite much of the left being against the notion). I'd also prefer an actual national ID (not the half-baked RealID programs, which some states still haven't adopted).
It's not really "much of the left" that is against it, just the loudest voices. Pew research says [1 sorry for the ugly URL]
Support for photo ID requirements also remains widespread in both parties. More than nine-in-ten Republicans (95%) and about seven-in-ten Democrats (71%) favor requiring all voters to show government-issued photo identification to vote.
I am p sure a lot of those that aren't for it aren't for it because of access to said ID is gated behind money (or unreasonably out of the way), which would need to be fixed first.
Without an ID, there's far more than just voting that they're not able to take advantage of. Yet I never hear of anyone having trouble living in this modern world that requires an ID for just about everything.