If the Democrats were better at politics, the current tax standoff would be a HUGE boon for the Democrats. They could say with reasonable honesty that Republicans opposed tax cuts for the poor, the middle class and the upper middle class. The fact that Republicans only opposes those cuts because they wanted to hold them hostage to get tax cuts for millionaires is actually worse. Rather than opposing the proposed cuts as a matter of ideology, it's simply a political strategy to get tax cuts for the top percent or so of Americans. That doesn't make the Republicans look too in favor of the folks they claim to look out for.
However, this isn't a win for the Democrats because Democrats SUCK at this kind of thing, and Republicans are really good at it. And while I'd rather the debate be intelligent and fact-based, the fact is that the average voter is won over more by a good story than anything else. The Republicans tell a story that they support "small business" and "average Americans", and despite being handed a gift wrapped argument to the contrary, Democrats can't manage to make use of it.
Democrats should be on TV 24/7, demanding that Republicans explain why they're supporting a tax hike on the vast majority of Americans. Make Republicans say what they really care about is tax cuts for millionaires, and they're willing to jack up YOUR taxes if they don't get their way. Except Democrats have never been good at that argument, and it doesn't look like they are going to start now.