The USA, in common with most countries, has laws against "obscene" publications. Publishing is interpreted very broadly, and would include internet distribution.
Crucially, in the USA "obscene" material is not protected by the First Amendment, following the 1973 ruling in Miller v California.
Lee is targeting the Miller Test from that case. This is a three part test used to decide if something is "obscene" or not.
- Whether "the average person, applying contemporary community standards", would find that the work, taken as a whole, appeals to the prurient interest
- Whether the work depicts or describes, in a patently offensive way, sexual conduct or excretory functions specifically defined by applicable state law
- Whether the work, taken as a whole, lacks serious literary, artistic, political, or scientific value.
Lee is trying to get rid of the first part, and remove the "patently offensive" test and instead define as obscene anything which
...depicts, describes or represents actual or simulated sexual acts with the objective intent to arouse, titillate, or gratify the sexual desires of a person
Again, this isn't going to go anywhere. The USA isn't a theocracy, even if some lawmakers wish it was.