If the past decade of elections have taught us anything, it’s that neither party can accurately predict a tidal change in voting behavior. Trumpeting about it before it happens is advertising and nothing more. It’s an emergent result, not a predictable phenomenon, and a dangerous prediction, regardless - never give anyone a reason to not vote, especially baseless optimism.
Don’t rely upon it happening, MAKE it happen by voting, and enjoy the hell out it should it arrive.