(CNN) An "unshackled" Donald Trump makes Hillary Clinton's top aides happy, but it does come with concerns, they said Tuesday.

They are worried that a negative, race to the bottom with Trump could stifle turnout, arguing that it has become clear to them -- especially over the last 48 hours -- that Trump's strategy is to run the race into "the sewer."

The thought goes like this: Trump scorches Republicans, gets nastier with Clinton to the point that she has to respond, voters get turned off and decide that they've had enough with this election -- so they don't vote.

"I think that this seems to be their strategy, disgust everyone with our Democratic dialogue so that they won't come out to the polls," John Podesta, Clinton's campaign chairman, told reporters aboard Clinton's campaign plane.

He added: "I think it is very unbecoming a presidential candidate. I guess he fires up the people who go to Alex Jones and Breitbart. But I think it is very unbecoming."

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