The hesitance of some House Democrats to hold a vote on extending those parts of the Bush tax cuts that benefit people earning less than a quarter million dollars a year is genuinely bizarre. The public opinion landscape here is crystal clear. People overwhelmingly approve of the tax cuts benefitting people earning less than $250,000. They overwhelmingly disapprove of the tax cuts that only benefit people earning more. One conservative Democrat tells Greg Sargent that voting for the middle class tax cuts is dangerous because it will be seen as a vote against tax cuts for the rich:

"I don't think it's the right vote," Matheson told me, adding that he only backed holding a vote on letting all the tax cuts expire. Matheson said a vote on just the middle class tax cuts is tantamount to letting the tax cuts for the wealthy expire.
"You're letting other rates go up on January 1st," he said. "I think we're better off if we don't do that."

In other words, he's afraid to vote for something that's popular because it will be seen as a vote against something else, that happens to be unpopular.

Now, if you read between the lines of Matheson's comments to Sargent, as well as similar comments by a conservative Democrat to Jonathan Cohn, you see that they're actually afraid of the "small business" canard. You vote for a middle clas tax cut, and you get accused of raising taxes on small business.

Well, there's a simple solution to that: hold two votes. First have a vote on the tax cuts for all income under $250,000. (That of course, also provides significant tax relief to upper-income taxpayers. Indeed, under that plan, the rich would get more than the middle class in total dollars):

Then you hold a separate vote on tax cuts exclusively for people earning more than $250,000 a year. Anybody who wants to vote for that can vote for that, too.

Remember, the uper-bracket tax cuts are unpopular. The only way the Republicans pass them is to combine them with middle-class tax cuts, then use the former to pass the latter. The whole tactic is to combine the two in order to put the GOP at an advantage. The Republican game is to hide their political shit sandwich in your ice cream sundae. Why let them play that game? Keep the two separate and let people decide which they want. There's no possible advantage for Democrats in combining the two.