[ZenoArrow]

Violent uprisings make things worse, because even if they succeed they often leave behind a massive power vacuum, that some people are only too glad to try to fill.

However, peaceful uprisings have shown to be far less problematic. Think about the revolutionary movements led by Gandhi and MLK.

I see no evidence that a Sanders presidency (or a Trump presidency, for that matter) would lead to a violent uprising, so I'd suggest it's fine to calm down a bit, you're unlikely to see America fall apart (or at least, you're unlikely to see it fall apart because of a new president).