Go on. Show me a video game that's interactive porn widely available in the US. Bonus points if it's rated E so that a 10 year old can actually buy it.
He can't, because there are none, unless you reeeaaallly stretch the definition of "porn." Even the most "adult" mainstream games out their (GTA, etc) are at most the equivalent of an R-rated movie in terms of adult content.
Not only that, but very, very
few games have ever been rated AO (Adult's Only) by the ESRB, and even then, all of the large retailers have a policy of not selling AO-rated games.
The industry policies itself just fine. There is no need for the government to unconstitutionally intervene.
Also none of the console makers will allow a AO rated game on their console, so it would have to be a PC game.
I've never seen an AO rated game before, I guess most of them (at least these days) you have to download.