The biggest story from last night's debate wasn't Marco Rubio's strong performance (which it was), Ted Cruz stealing a moment (which he did), or the candidates and GOP audience attacking the media (which most definitely happened). Rather, the most significant story from last night is that Jeb Bush's campaign now finds itself on life support, especially after Bush swung and missed when trying to hit Rubio over his Senate voting record. As one Republican operative told NBC's Peter Alexander, Bush had to demonstrate to his supporters and donors - after a rough last few weeks - that the former Florida...