My guess is the 5 million lines of code refers to the total lines of code and only some portion will need to be changed. I laugh my ass off when I watch the media try to explain technology.
Just like years ago, when Greta Van Susteren would appear on CNN and serve as a legal expert and try to explain things in non-technical terms, the press needs someone who can understand what's going on with the entire AHCA mess and explain it to people. Most of the people in Congress wouldn't know an OLAP Cube from an Ice Cube and probably think that object hydration is something they do during happy hour.
