https://fivethirtyeight.com/features/will-democratic-incumbents-lose-despite-the-blue-wave/I highlighted something important in the first quote: Incumbent Senators from the "out" party rarely lose, even when they are from states that lean heavily towards the other party. This is not a theory - it is a fact. This would mean that it would be highly unusual for Democrats to have a net loss this cycle, and based on the results over the past generation, it would probably be a better bet to say that they won't lose a single incumbent
(vs losing 1 or more).
It's an interesting article nonetheless. Perhaps this is the first election in decades where the out party loses a handful of incumbent Senators, or perhaps Democratic Senators are actually in a better spot than polling reflects and will cruise to reelection in November. We'll see!
