What do you think the betting lines are based on? Right now all the actual betting lines favor D for the house R for the senate, because they're based on the same things everyone has been using. People forget that just because something is 99% likely it doesn't mean it WILL happen or that if it doesn't the person was wrong. It just means it's the 1% situation. That's the whole point - POTUS is an anomaly, so you need to "expect the unexpected" so to speak. What worked for prediction in the past doesn't hold, and everyone is still catching up. I don't disagree with the author, but note that they are a former odds maker and don't offer actual odds. They're just basically pointing out the above.