There was a Politico article about this last week:

https://www.politico.com/news/magazine/2023/08/08/age-law-online-porn-00110148

The public is also on her side. “You poll this, it’s like an 85-15 issue,” explained Jon Schweppe, the policy director for the socially conservative think tank American Principles Project. Age-verification for porn is not his think tank’s only priority, but when they poll it against other priorities in swing states, age-verification blows the rest out of the water, with 77 percent in support and 15 percent opposed.

Here’s a Pew survey suggesting that the majority of Americans consider porn harmful:

A large 70%-majority of Americans reject the idea that “nude pictures and X-rated videos on the internet provide harmless entertainment for those who enjoy it”; only 27% agree; in general, opinions about pornography have become slightly more conservative over the past 20 years. Currently 41% agree that “nude magazines and X-rated movies provide harmless entertainment for those who enjoy it,” while 53% disagree. The number saying such material is harmless has fluctuated, declining from 48% in 1987 to 41% in 1990 and then varying by no more than four percentage points thereafter. The pattern is more mixed for other values related to freedom of expression.

Note that trends in this space are getting more conservative, rather than less. This tracks with my experience with Gen Z.

Admittedly, I have not seen any polling about specific legislation. It hasn’t been long since these bills were passed, and I don’t know if it’s a priority for pollsters. But if nothing else, just look through the thread. Lemmy leans way further left that the general public, and even here most people’s problems with it are about execution rather than intent.

I have a source: https://www.statista.com/statistics/1365965/us-adults-support-online-age-verification-by-gender/

68% of people either Strongly or Somewhat support verification mechanisms for online content.