Another problem for far-left liberals is that they demonstrate an insatiable appetite for eating their own. Another Gallup poll, also released on Thursday, found a worrisome trend: President Obama’s approval rating among liberal Democrats, while still high, has slipped 10 percent since Nov. 1; but, among moderate Democrats, it has held steady.

I attribute much of this to the across-the-board, over-the-top scoffing by the ultraliberal, self-professed brains of the party. According to them, Obama must pay for abandoning his “progressive base.” That’s funny because progressives, many of whom really wanted John Edwards to be the nominee in 2008, only constitute 20 percent of Democrats.

To adapt a phrase from Bill Maher, these far-left liberals would rather fight the friend who disappoints them than focus on the enemy who wants to destroy them. That’s not so for those on the right. They just want to win. Too many liberals just want to whine. It’s like they’re perpetually humming the chorus to Lesley Gore’s hit from the ’60s: “It’s my party, and I’ll cry if I want to.”

Sadly, if the Democrats’ big tent of openness shrinks to a little fortress of liberalism too fast and too soon, they may well have a reason to cry.