Because shes not. All Pollsters are graduates of Liberal Schools. There is No QA for polls.. They can make up all they want and all they get paid to do.
Several Modern polling Firms like the one Balletpodia just used do not even pretend to be legit, They brag they do not measure but manipulate to deliver results.
Bottom line Pollsters think people are stupid and herd animals who can be controlled.
I know, polls can be skewed to get any result you want, but the poll that has me shaking my head the most is the actual ballot box. How could even democrats fathom that this would be a good idea to nominate her?
Don't take offense to this, I knock myself also, but during the Great Trump/Cruz wars of spring 2016, we have accused each other of being Koolaid drinkers.
These Democrats drink it by the barrel, go swimming in it, and have stock in Koolaid!
Democrats are SJW's and "gimmedats" so I guess there is always that, I get it (if I was liberal, and thought that was the correct way of thinking),but to elect criminals is just insane.