Pueblo, Colorado (CNN) Hillary Clinton told voters Wednesday that she can't believe Donald Trump has the "gall" to run for president demeaning the United States while paying little to no federal income taxes.

Clinton, speaking to a fired up audience in at the Palace of Agriculture in Pueblo, Colorado, also slammed Trump's campaign for a recent uptick in negativity and telling The Wall Street Journal that they plan to use a "scorched-earth" strategy to try to depress Democrats into not voting.

"His campaign said today that they are going to use a 'scorched-earth" strategy for the remaining four weeks of this race," Clinton said. "Now this just shows how desperate they are, that is all they have left, pure negativity, pessimism."

She added: "We are not going to let Donald Trump get away with it, are we?"

Clinton's top aides have begun to worry that Trump's strategy may be effective, though, worrying that they will be able to turn the election into such a revolting slog that Democrats will decide to just sit out the race entirely.

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