Hillary Clinton has always been her own worst attack ad. Quotes like this are an example of how she does more damage to herself than anyone else could.
"My work as secretary of state was not influenced by any outside forces. I made policy decisions based on what I thought was right," Clinton said. "I know there's a lot of smoke and there's no fire."
Of course the most popular version of that quote is, Where there's smoke, there's fire.
Hillary Clinton is conceding that she has the appearance of wrongdoing while insisting, contrary to public impression, that there's no actual wrongdoing. That's a bad position for a presidential candidate to be in. And yet Hillary made the admission of her own free will.
She's reduced to arguing that even if she looks crooked, she isn't.