The flipside of David’s Frum’s piece about the stupidity of the right was provided by Jonathan Chait, writing about the unreasonableness of the left. On the whole, I agree with Mr. Chait’s analysis. But I really feel like he missed something by going all the way back to FDR to show how liberals have been unhappy with every Democratic president in recent history.

In any broad historical piece, you’re going to run into definitional problems of what constitutes the left, or the liberal left, or the progressive movement, or even the Democratic Party. I don’t think you can talk about the left’s relationship with the Democratic Party in the same way pre- and post-Vietnam, or pre- and post-Civil Rights Era. Mr. Chait may be right there there are certain personality traits among liberals that have remained consistent throughout, but the liberal left changed fundamentally during the 1960’s. In the 1930’s and 1940’s, the liberal left was the intellectual soul of Democratic Party. It had to cobble together an uneasy coalition of socialists and Jim Crow Democrats and city bosses and ward heelers. But liberals were in charge of the big things, like implementing the New Deal, creating the United Nations, and setting up the Bretton Woods system. While liberals agitated for social reforms and found themselves stymied on many fronts, they didn’t feel completely left out of power. In many areas, they wielded power. And if we look back now with the benefit of hindsight, we can see that the liberals were on a victorious march towards ending apartheid in the South and winning much of the argument over social policies with Lyndon Johnson’s Great Society. There was something of a liberal consensus in this country. At least, there was enough of a consensus for liberal ideas to win the day.

But then came Vietnam. That stupid war destroyed the liberal consensus. It created a counterculture. And that counterculture is where liberal legitimacy went to die. You cannot be a governing philosophy at the same time that you are countercultural movement. A countercultural movement is set up to oppose power. It is a critique of a country, not a platform for governing a country. And that’s where the left has been stuck since about 1968. This is something distinct from Will Rogers’s old saw about “I’m not a member of any organized political party, I’m a Democrat!” This isn’t just about herding cats. It’s a fundamental flaw in the progressive predisposition.

There are virtues in the progressive attitude toward power. Most obviously, you can look at the way Republicans will follow their leaders over cliffs to see what happens when you don’t have a healthy skepticism towards your own party’s leaders. But neither lemming-like obedience nor chronic dissatisfaction are smart or healthy political attitudes.

It’s easy to fall into lazy criticisms, like the Republican mantra that progressives blame America first and don’t believe in American Exceptionalism. But there is more truth to those criticisms than progressives are willing to acknowledge. What progressives need to do is find a way to make the countercultural cultural.

How do you do that? Some recent examples of how this has been done successfully include moving from the Stonewall Riots in 1969 to the repeal of Don’t Ask, Don’t Tell and the refusal to enforce DOMA in 2011. Or, moving from the Civil Rights Act of 1964 to electing a biracial president in 2008. What was unthinkable has become part of our culture. Likewise, assuming the Affordable Care Act survives all legal challenges and isn’t destroyed by a Republican president, it will form part of our culture and join Medicare and Social Security as things that are taken for granted.

We need to act like we trust power to do great things, and project that we are the right people to hold that power. And we need to take our positions within that power coalition rather than positioning ourselves as always outside of it serving as the gadfly.

Liberals used to be able to do this. But since the disaster in 1968, it seems like we just want to attack all forms of power, even when they are our own.