I think you are right. It simply reinforces the notion that the entire DC establishment is corrupt.
There have been several polls on this issue, and in every one of them, a majority (albeit a slim one) said that Clinton did something illegal.
Most of the remainder said it was unethical, but not illegal. Less than 1 in five said she did nothing wrong.
However, Trump's numbers were inverted: a majority said "unethical, but not illegal", and less than 1 in five said he did nothing wrong.
I just can't see a significant number pulling the lever for Clinton while believing she did something illegal.