Hillary Clinton will only debate Bernie Sanders in New York ahead of that state’s primary next month if the Vermont senator changes his tone, Clinton’s chief campaign strategist said Monday.

“Let’s see the tone of the campaign he wants to run before we get to any other questions,” Joel Benenson said during an interview on CNN when asked whether Clinton would debate Sanders in New York.

On Sunday, the 74-year-old democratic socialist and his campaign manager directly challenged the former secretary of state to a debate in the Empire State ahead of its April 17 primary.

The pair have agreed to debate at some point in April but have not nailed down a date or location. Sanders is eyeing New York because of its sizable number of delegates and because Clinton leads there by a large margin. A big enough win in New York — which elected Clinton to the Senate in 2000 — will all but assure her of winning enough delegates to claim the Democratic party nomination.

In defending Clinton’s refusal to commit to a New York debate, Benenson asserted that Sanders is running a negative campaign.

“Because I think the real question is what kind of campaign is Sen. Sanders going to run going forward,” Benenson said, adding that Sanders “spent about $4 million running negative ads” ahead of the March 15 primaries.

“This is a man who said he’d never run a negative ad ever. He’s now running them, they’re now planning to run more,” Benenson continued.

The Clinton campaign regularly accuses Sanders of running a negative campaign even though there appears to be little evidence supporting the claim. Sanders has hammered Clinton over paid speeches she has given to Wall Street banks. But Clinton and her surrogates — including former President Bill Clinton — have been as aggressive against Sanders, if not more so.

Asked what Clinton risks by debating Sanders in New York, Benenson remarked that “there’s no risk.”

“She’s done very well in the debates. The debates have been very good, but Sen. Sanders doesn’t get to decide when we debate, particularly when he’s running a very negative campaign against us,” Benenson said.

“Let’s see if he goes back to the kind of tone he said he was going to set early on. If he does that, then we’ll talk about debates,” he added.

[dcquiz] Benenson did not completely rule out a New York debate, however.

“We’re going to see what kind of tone he sets,” he reiterated.

“If his campaign wants to run the kind of negative campaign and run negative ads like they did in North Carolina, Illinois, all over the country on March 15, that’s going to be disappointing to a lot of Democrats.”

Benenson has another dog in the fight against Sanders. His public relations firm, Benenson Strategy Group, counts Bank of America and J.P. Morgan Chase as clients.

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