How do you define an attack ad? Is Hillary Clinton attacking Bernie Sanders, in her most recent ad? In it, she declares “It's time to pick a side, either we stand with the gun lobby, or we join the president and stand up to them.”

Or how about this one from the Sanders campaign, released Thursday, where the Vermont Senator says, “There are two Democratic visions for regulating Wall Street. One says its OK to take millions from big banks and then tell them what to do.”

Bernie Sanders was back in New Hampshire yesterday to announce a new endorsement and speak to a crowd at Dartmouth College. The short trip to the Granite State comes as Sanders’ campaign is riding high, buoyed by strengthening poll numbers against Hillary Clinton nationally, in Iowa and New Hampshire. And as the race gets tighter, both campaigns are sharpening their elbows.

Jeff Weaver, the manager of the Sanders campaign, carefully points out nobody in his ad names Clinton as an example of this first vision of the Democratic party, despite protests from the Clinton camp.

“It was a little bit shocking the Clinton campaign seems to see itself in that first characterization,” he explained at a campaign stop at Dartmouth College, “So that's not something where we put them, but they put themselves there.”

It doesn’t take much to see that, in both cases, the un-named just off-screen target of these ads is the rival Democratic candidate. But no names are named, so some sort of plausible deniability is maintained.

With less than a month to go before the New Hampshire primary, this is the state of the race for the Democratic nomination: less collegial, more aggressive, both sides willing to wield direct critiques of each others’ record and tone.

The Clinton campaign lashed out at Sanders for the perceived Wall Street slight, and Sanders responded with at a press conference in Hanover yesterday. “This is not a negative ad,” he said, “Everybody knows that there are two divisions... there is a division in the Democratic Party.”

One might ask, why are the campaigns arguing about the semantics of what counts as a negative ad? Well, perhaps it’s because the dynamics of the race are very different than just a few weeks ago.

“I get a charge out of him, I really do,” said Andrew Johnson, one of what the Sanders campaign says was the 1,900 people who came to see the Vermont Senator at Dartmouth. Johnson says, he's only recently decided that he'll vote for Sanders.

“You know he's been fringe for a while, but he's gaining momentum now, and definitely is now viable as a candidate.”

All through the campaign, there have been Democrats saying, "Well, I like Bernie, but... the general election."

Sanders’ history as a self-described Socialist andhis distance from the political insiders seemed to disqualify him. Now with Sanders’ gap against Clinton narrowing in Iowa and nationwide, and a solid lead in New Hampshire, many of those Democrats are feeling safer casting their lot with their first choice.

For the true believers this is no surprise.

“We've kind of known all along that this was going to happen,” says Doug Deaett from Hanover, who has been volunteering with the Sanders Campaign. He says the people he talks to while promoting the candidate agree with him on the issues.

“It was kind of like a submarine campaign, you know, he's been under the radar, but we knew he was going to pop up real soon... and it's just happening the way he planned it, you know.”

“When we began, we had no money, we had no organization, we had very little name recognition around the country... other than that we were in pretty good shape,” jokes Sanders from the stump in Hanover. “Well, a lot has changed in eight and a half months.”

Whether or not Sanders was planning to trail in the polls until just weeks before the first contests, he's certainly not complaining now. And this is likely what explains the change in tone of the campaign.

Gone are the days where Clinton can campaign without mentioning Sanders' name.

Instead, both sides quibble over what constitutes a negative ad. And as they do, the few remaining days to the New Hampshire primary slowly tick by.