I've been watching the latest season of House of Cards and in the latest episode I saw there is a line that I think is supposed to convey an image, but I can't quite understand it. It is about the US president in an election and the family of his opponent. It goes like this:
The Conways are everything everyone wants to be, You are what everyone wants to become.
So, what is the difference between the "be" and "become" here?