Maybe it’s too mind bending to contemplate responding to Andrew Sullivan (a reasonably clear headed conservative) responding to David Brooks (a nearly completely muddle-headed one, at least most of the time), but this is a clear illustration of the rhetorical corner that both conservatives and some progressives have painted themselves into at this point.
There’s two big problems here. Problem the first:

“[opportunity] is the authentically liberal vision: government taking care of its citizens, as parents take care of children. My vision is one where the government leaves its citizens alone as much as possible, and treats them as self-governing adults.”
This is the borderline nonsensical endpoint that results from dragging the “government as family” analogy too far into the deep end. The nurturant family model put forward by George Lakoff can too easily be used to create a straw man framework of progressivism that’s easy for conservatives to hammer away on. Progressive don’t want a “nanny state” any more than parents want to be responsible for building schools and hiring teachers or constructing highway interchanges and transit systems for their kids. Maybe this seems obvious, but since there’s clearly been some confusion: it’s a metaphor, people. Parents and the government have different roles in society. Government isn’t like a hug! Yes, we want reasonable regulations on the market. Yes, we want funding levels for education sufficient that we can compete in the 21st century. Yes we want progressive taxation. But no, we do not want our elected representatives to tuck our kids in it at night.
Problem the second:

The point of freedom, to my mind, is to live in the constant presence of insecurity, indeed to embrace such insecurity. That to me is the essence of America: the nerve to live with insecurity. Life is insecure. The goal of America is for individuals to gain the self-knowledge and nerve to live with that insecurity. That can’t be given to anyone; it has to be earned by each of us, as best we can.

I don’t know exactly what the point of freedom is, and I don’t think I can: I think it’s a deeply personal concept that conservatives have done horrible damage to in attempting to redefine it as “owning lots of stuff” or “ability to pollute as vigorously as I’d like.” But I do know that for most folks, the ability to feel insecure is nowhere near the top of the list of our priorities. Not even close.
What freedom might be: Expanded capability for intimacy, maybe. Greater ability to contribute to society, almost definitely. Wider capacity for pleasure, sure. But feeling insecure? Feeling like my health or family or life or shelter might be taken away? No. No thank you. I don’t know Mr Sullivan’s biography but these sound like the words of an elitist who not only hasn’t faced many personal difficulties, he lacks the ability to empathize with those who have.
Conservatives have an overwhelming tendency to forget a big component of success: luck. All their talk about bootstraps and whatnot always seems to work around that issue and leave it out. Sure hard work is a component of success, but what gives someone the ability to and desire to work hard? There’s always an element of luck in the equation somewhere.
What we do want is a change of focus. Hypercapitalism has gotten sufficiently out of hand that it’s affecting people’s capacity for intimacy. Hypercapitalism is literally tearing families apart, driving divorce rates up, whacking the middle class. Conservative prefer to blame some kind of vague “60s permissiveness” for this but there’s simply no data to support this, while there are piles of it to support the role super-sized capitalism is playing in tearing our society apart.
The problems with our overrevved economy are backed by data and the overwhelming majority of Americans want solutions that moderate it’s ill effects. The Center for American Progress sums it up like this in a memo from last year, Voters Deeply Concerned About Rising Materialism and Self-Interest in American Society; Desire Government Focused on the Common Good and Basic Decency and Dignity of All: 92% of Americans think we’re becoming too materialistic. And what is the point of risk other than to increase our material prosperity? Insecurity for insecurity’s sake? The fixes for this won’t be completely through the government, but a different, more positive view of the expression of our collaborative interests – in other words, democracy – could certainly start to move us in the right direction.