There is probably no one in the United State that has a politically clean image by the time they are campaigning for the presidency. Usually, by the time they become a candidate for presidency, they had to go through a lot of lying and deception to get to this point.
Therefore, her image is probably not clean. Also, during their campaigning, many people come out to say all of the bad things that the candidates have done in the past. Hilary is no exception. Her political image was damaged when she created an email system and used it while she was secretary of state. Then after she lost the election, she blamed her party for her loss. That will continue to haunt her.