Aides say candidate will not ‘become a hitman’ targeting Hillary Clinton as they hope he can shift from impassioned speeches to conversation

Out on the campaign trail, Bernie Sanders’ full-throated attacks on the billionaire class have been so loud and passionate that aides have taken to offering him honey, to help soothe noticeably wrecked vocal cords.



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But when he takes on Hillary Clinton for the first time, in a television studio in Las Vegas on Tuesday night, staff members are hoping he will bring his indoor voice instead of the gravelly bark that has electrified record crowds at rallies.



After meeting Sanders and his wife, Jane O’Meara, at their home in Burlington, Vermont, two weeks ago to discuss tactics for debating the former secretary of state, staffers prepping him are hopeful he knows the difference.



“[His] experience of doing Sunday shows, being asked substantive questions in a live television environment – which is not a shouting environment, which is a talking environment – he’s done a lot of that … and I think the debate is a lot like that,” his senior adviser, Tad Devine, told the Guardian.



“Just because you are standing at a podium doesn’t mean you should give a speech. You need to really think about this, as though you were sitting at a table talking to somebody.”



Although they have decided against the kind of formal dress rehearsals favoured by Clinton and other presidential debate participants, Sanders aides have been working hard on how to counter Clinton’s recent shift to the left on a number of issues that would once have been easy targets.



The most dramatic of these came less than a week before the debate, when Clinton announced an about-turn on free trade and adopted much of the same opposition to Barack Obama’s Trans-Pacific Partnership (TTP) deal that has made Sanders popular among progressive Democrats and trade unions.



But aides insist he will not “impugn terrible motives” for such changes, preferring to welcome a convert and merely point out that the policy reversal would have been more useful while Congress was still voting on authorising the trade negotiations.



“Bernie is not going to become a hitman,” said Devine, who helped run the presidential campaigns of Al Gore and John Kerry and has been leading the Sanders debate prep alongside campaign manager Jeff Weaver.



“He is not going to go out there and start attacking. It’s against everything he believes in and stands for when it comes to campaign politics,” added Devine.

“Having said that, he will point out the differences, whether it’s past policies like the decision to invade Iraq or present differences, like their plans for college [fees].”



Sanders rehearsed a similar argument about Clinton’s late opposition to the Keystone oil pipeline extension during his latest television interviews on Sunday.



“From day one, I opposed the Keystone pipeline because I believe that if you’re serious about climate change, you don’t encourage the excavation and transportation of very dirty oil,” he told NBC’s Meet the Press.



“People will have to contrast my consistency and my willingness to stand up to Wall Street and corporations, big corporations, with the secretary,” he said.



But advisers said such unwillingness to play hardball does not mean the Vermont senator will not defend himself if he is attacked for being too extreme or leftwing, as has happened in his previous election campaigns.



“I don’t think Bernie is going to be a guy who is going to be milquetoast. If someone wants to challenge his record or challenge his issues, he is going to be vigorous on both,” said Devine.



“These things can get heated sometimes, particularly if one or more people start coming at you, and we certainly saw that in 2008 with Obama and Hillary.”



A veteran of Democratic campaigns going back to Jimmy Carter, Devine is valued for being one of the few members of the Sanders team not to come from Vermont. But he also inadvertently highlights another pitfall for the 74-year-old challenger.



While many male politicians are routinely called by their last name, Secretary Clinton is still often referred to in public as Hillary, a slight that is unlikely to go unnoticed by many Democratic voters if it is repeated on Tuesday night.



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Sanders has generally shown himself careful to treat his opponent with respect, almost always referring to her as “Secretary” in public, but his largely male staff is nonetheless keen to stress his “authenticity” – a word frequently used to attack Clinton in ways her supporters argue is sexist.

“People like the fact that he is authentic and genuine, and ‘in the moment’ – that’s what makes him so good at connecting to people,” said Devine, as he described how the team had decided to only practice opening and closing statements in front of a podium, rather than rehearse whole exchanges.

“If you come into these things with a lot of scripting, figuring out every word of an answer for 60 to 90 seconds, it translates poorly if the heart of your campaign is this very authentic guy.”