young folks have clearly heard the message, as they have broadly rejected the Democrats in return.
You wouldn't know it by the data.

But this is an age-old story. Millennials were far more Dem-leaning 15 years ago, during the Obama Era. Boomers were more Dem-leaning during the Clinton Era. Great Depression voters drifted from FDR to Nixon in the intervening 30 years.
There’s a reason the Democrats are polling even lower than Trump
Sure. They've lost the mandate of Corporate Mass Media as media has been consolidated in the Tech Sector and the Techies have nakedly embraced Randian Objectivism.