You learn a lot about a candidate when they lose an election. Bernie’s campaign hit a wall in Nevada and after huddling with his campaign advisers (we assume) to determine his strategy going forward, he has come out swinging even harder at Hillary’s integrity.

Unfortunately for Bernie, this will only further degrade his brand. He promised to run a positive campaign, but there’s absolutely nothing positive about accusing someone of being on the take – with zero evidence.

As we’ve argued: assume for the sake of argument that each Democratic candidate has a 50% chance of winning the nomination. And assume the Democratic nominee will face someone like Donald Trump in the general election. With so much on the line, why is one of them waging an all-out war on the other’s integrity?

During the most recent Democratic debate, Hillary confronted Bernie on his continued insinuation that she is somehow tainted by financial industry contributions, something he repeated in a news conference today.

Hillary’s point is undeniable:

[Barack Obama] was the recipient of the largest number of Wall Street donations of anybody running on the Democratic side ever. Now, when it mattered, he stood up and took on Wall Street. So, let’s not in anyway imply here that either President Obama or myself, would in anyway not take on any vested interested, whether it’s Wall Street, or drug companies, or insurance companies, or frankly, the gun lobby to stand up to do what’s best for the American people.

Every time Bernie uses the Wall Street dog whistle, he’s indirectly smearing President Obama. Or, worse yet, he’s accusing a woman of doing something that he gives a man a pass for.

A week ago we wrote that no matter how lofty and inspiring Bernie’s message, no matter how much he motivates younger voters, it is deeply unjust – and frankly, reckless – to run a campaign premised on the destruction of Hillary’s character through false innuendo.

Earlier today, Bernie’s top surrogate, Cornel West, said the following:

“How many politicians do we know have genuine integrity. You can count them on your hand, and Hillary Clinton is not one of them. She’s not one of them, brother.”

Make no mistake, Bernie’s campaign message and the behavior of his supporters have become less about something and more against someone. His path to victory runs right through Hillary’s integrity. It’s a deeply regrettable turn of events in an election where Bernie had initially vowed to stay positive and issue-driven.

And no, Hillary isn’t reciprocating. Her criticisms are about drawing a contrast with Bernie’s unrealistic proposals, to bring a dose of reality to the dreams he’s selling to eager young voters.

There is no Bernie revolution. Democratic turnout is down. There is nothing but the harsh truth that America could veer sharply right in November and we need our candidates intact, not mangled and battered.

Lest any Bernie supporter question this premise, they should first explain this:

In a story in Sunday’s New York Times, Bernie Sanders’ top adviser, Tad Devine, took a very nasty shot at Hillary Clinton: “She cannot be trusted to appoint someone to the Supreme Court who will take the issue of campaign finance seriously,” he said.

Democrats just don’t do that to other Democrats.

Bernie is now presiding over a campaign and a contingent of supporters who are willing to treat Hillary more disdainfully than Karl Rove, the Koch brothers, and the GOP. Crossing that line is crossing to the dark side of politics. Surfing a wave of hate for one of the most admired and respected women on the planet is beneath him and beneath any true Democrat.

Bernie is showing questionable judgment by attacking Hillary instead of highlighting his own policies. The problem is he knows the latter isn’t working. And going harder negative just makes him look desperate.