1) It's possible that they don't know--not because the evidence  or information is unavailable to them, but because they are "Double Highs"-- authoritarian personalities who also very much want social dominance.
To question such a fundamental part of their reality structure is alien to the authoritarian mindset, and in fact seemingly unrelated to (or even damaging to) their central task-- to gain control.

2) They know- but the conclusions and policy options that emerge from that knowledge are so heretical, so fundamentally scary that they continue to opt for the band-aid box. These candidates have given their lives to playing a game.  Play long enough, and you come to believe. Now, that game is rapidly emerging as just another fantasy- a narrative- that has an inexorable life of it's own, and a lousy ending.

Will they opt for real change?
Can it be done? FDR swam upstream like a champ. Maybe Obama can too.

But--- What was it that Krugman said?
"Hope is not a plan".

The Geeze says:
"Hope, like life, is better than the alternative."  

Capitalism searches out the darkest corners of human potential, and mainlines them.