No, there won’t ever be a ban on tattoos, the Marines would never be able to reach their recruiting quotas if they did something like that. I was mainly referring to some of the spider webs on the elbow, or a tribal sleeve that covers the entire forearm. It most likely won’t affect your chances of getting in, just keep in mind that there are many conservative judgmental types out there. Someday, you will be compared against your peers for promotion, and if you have a lot of ink protruding from the sleeve line, I can assure you it will not give you any extra points. There are many officers with tattoos (including myself); however, I feel safe saying that tattoos are not an officer like quality. If you get something that can be covered up with PT gear, I would not have any worries about being turned down because of it.
As far as constitutional, keep in mind that you trade many of your constitutional rights for some of the privileges afforded to military officers. I can assure you that having a gang related, or satanic tattoo may be one of your constitutional rights; however, try and join the military with something like that. In one of the other discussions, there is already enough said about the military’s limitations to freedom of speech, so I will not say more than I already have.
All in all the only point that I am trying to make is that “prejudicial to good order, discipline and morale or are of a nature to bring discredit upon the Marine Corps” leaves a lot of room for interpretation. Draw your own conclusion. I got my tattoo between OCS#1 and OCS#2, and didn’t hear a thing about it, and I am also not worried about it effecting me in the future.