Biden says the Republicans don't want to talk about the issues. He's right. Instead, as Krugman notes, they're trying to make the Democrats the faces of a duplicitous, faceless "elite" that's oppressing the middle class. If this strategy works, it works by putting people in a mental bubble where anything that any Democrat says about the issues just won't penetrate, because it all comes through the emotional filter as "talking down", or "elite lies."
To counter this strategy, you've got to pop the bubble. Issue-talk itself, no matter how loud and proud, won't do that. You've got to point out who's really representing the elite in this campaign.
I'd happily trade all of this stuff and plenty more for one good, cutting remark about Cindy McCain prancing onstage at the Republican convention wearing earrings worth more than the median American house.
It's possible that the Obama campaign is reluctant to do this sort of thing because "families are off-limits", even though she was on stage at the frigging Republican convention. And maybe that's also the reason that McCain has just about completely escaped any scrutiny for failing to produce Cindy's tax returns --- even though anyone who lives in the real world knows perfectly well that her finances are also his. And if so --- would they have considered it "off-limits" to mention that Phil Gramm's wife was on Enron's board of directors, while Phil was doing their bidding in the Senate? You've got a campaign to win, guys, and politics ain't beanbag. Get over it.