I believe she is up by 6 points, just as I believe Bill Clinton “did not have sex with that woman”.
They’ve historically over sampled Democrats in the past, and have been fairly accurate. For what reason they over sampled them, I do not remember, but I believe it has to do with their tendency to turn out, but I could be wrong. Perhaps someone with a better memory can ‘splain.
What is NOT accounted for in most of these polls is most of them sample “likely” voters, i.e., voters who voted in the last election. Trump is drawing in a large number of people who have not voted before or recently.