At some point she's going to get swatted down by the democratic party. Until then she's disrupting the power structure. She is starting to see the dishonesty and hipocrisy from the inside. Her failing is one of lack of experience and subscription to textbook economics (i.e. idealism that doesn't actually work in the real world)
One of the reasons she is popular is she is a stereotype of what a lot of young people see in themselves. It's what naive democrats think they are getting when they elect someone, not knowing they really elected a corrupt pedophile who is amassing wealth by selling influence to rich donors, and passing laws that benefit those rich donors.
She may cause a rift in the democratic party before they squash her. Let's hope she does. You can't keep up her type of idealistic view of the world after being exposed to the reality of what's really going on.