The problem continues to be the stretching of definitions past the breaking point. If all babies are born sinners, and no babies are born (biblical miracle babies excepted of course) who are not sinners, then we have essentially removed meaning from the term "sinner," and made it synonymous with being a human being. If that is the case, then sin has no content. You're damned for what you are, not for what you do. You're damned for intellect and will even if you are born handicapped and with little or none to see, or if you are born unconscious and die an hour later. You're damned for the sin of Adam even if you are physically incapable of repeating it. If you're damned for a sin you cannot do, sin is meaningless.
To use the depravity of man as a species as an argument for individual damnation, not to mention the individual damnation of babies, is stupid. I don't care if Malcom Muggeridge or God himself said it. It's crazy.