I hate being a pessimist, but I’d rather be a realist than a fool. That being said, it’s time to learn about the Bradley Effect.
The Bradley Effect is where white voters poll as supporting a non-white candidate (or as undecided) all the way up to the election, but when it comes time to actually vote they go for the white guy. It’s a sociology thing; they want to be the progressive guy in public but when protected by anonymity the racism shows itself.
Make it part of your vocabulary; the Bradley Effect might just screw this country for another four years.