That's why I say 'very few' instead of 'all.' Does a 15-year-old have a stake in the real estate bubble and the related derivatives market disaster? That 15-year-old from 2007 is in the cohort of first-time Presidential voters this year. Not in any direct way they don't, some whose families were affected would have an opinion on it based on their own life experience rather than hearsay, but no, the vast majority don't have an experiential knowledge of it, only whatever filters down to them from media snapshots of memory and current retrospectives and discussion of it in family circles and school social studies classes. It is not real to most of them in the same way it is real to someone who actually had their life savings wiped out or lost their home. These are kids who really just remember two Presidents in their lives, G. W. Bush and Obama, and Bush is a fading memory.
And even to an inexperienced and unskeptical mind, with Liberal teachers and media trying to fill their heads with goo, there is a disconnect to the idea that one President has the power to make the economy turn to suck, but the next President somehow doesn't have any power to make it not suck in four long years.
The Blame Bush game isn't going to move the needle on their turnout for Obama. I do hope the Dems waste a lot of effort on it though, rather than something that might actually work.