Cutting taxes exclusively on rich people is unpopular:
Normally you see “moderates” flocking to popular positions, especially when—as in this case—the popular position is also a genuine bit of difference-splitting middle ground. But that’s not the case here. Jon Chait speculates as to why:
One possibility is that vulnerable red state Democrats are trying to signal their moderation by breaking with the party leadership on a high-profile issue, even one in which the party has a popular stance. But the defections include retiring Democrats like Bayh and Conrad, and a blue state Senator like Lieberman whose main political danger comes from the left.
So my explanation is that Senators are both among, and surrounded by, the small minority of Americans who earn more than $250,000 a year. They hear from them disproportionately, they live among them, and they are them. So their conception of what is popular and what is reasonable on this issue is warped.
There’s something to that. But I think larger issue here is the perverse framing of deficit issues. If Mitch McConnell were sponsoring a bill to cut taxes on rich people and cut spending by an equal amount, I bet no moderate Democrats would find that tempting. And if Mitch McConnell were sponsoring a bill to cut taxes on rich people and raise taxes on the middle class by an equal amount, I bet no moderate Democrats would find that tempting either. But of course a permanent reduction in rich people’s taxes implies reductions in spending or higher taxes on the middle class. And the media never—never—frames a division within the Democratic caucus as pitting spendthrift moderates like Evan Bayh and Ben Nelson against deficit hawk liberals like Bernie Sanders and Barbara Boxer even though this is the precise divide that opens up whenever Bush-era tax policies are on the table.