We know that David Duke supported Trump. We don't know of anyone associated with the KKK supporting Hillary. That the voters don't care is to their discredit.
We do know of Hillary's mentor, he claimed to have left the KKK. We know of other KKK Grand Master who have claimed to have donated to Hillary. It's all just claims and accusations to smear the opposite opponents in the election cycle. These are not important issues. Voters knows these are just election smears.