Bernie Sanders has decided to go hard negative in the aftermath of Hillary Clinton’s historic Iowa victory. Problem is Bernie doesn’t do negative well. It’s not his brand and it’s not his message.

For all of 2015, Hillary and Bernie put the GOP to shame with a healthy, uplifting, respectful debate about issues that matter to working Americans. The lead-up to Iowa intensified, with both sides drawing sharper contrasts. But for the most part, the Democratic candidates have run a remarkably amicable contest.

Until now, that is.

The post-Iowa tone has taken a decidedly negative turn, with Bernie questioning Hillary’s core beliefs, not exactly something Democrats take kindly to.