All these changes push in the same direction. The basic thrust of liberal public policy over the last century is to keep in places the market system but use government to slightly mitigate against risk--the risk of getting sick, the risk of outliving your savings, the risk that you just won't make much money in the first place. The downside of these policies is that, in order to mitigate the downside risk, you also have to mitigate the upside benefit. If you're unusually rich, you have to pay a somewhat higher tax rate than most people. If you're unusually healthy, you have to subsidize medical care for people who aren't. If you were able to invest well enough to cover your entire retirement, some of your good fortune will be siphoned off to those who weren't. The rewards for getting rich, or merely being born rich, will remain enormous, just slightly less so than in a completely free market.

Republicans want to eliminate these mitigations of risk. Ryan would retain some bare-bones subsidies for the poorest, but the overwhelming thrust in every way is to liberate the lucky and successful to enjoy their good fortune without burdening them with any responsibility for the welfare of their fellow citizens. This is the core of Ryan's moral philosophy:

"The reason I got involved in public service, by and large, if I had to credit one thinker, one person, it would be Ayn Rand," Ryan said at a D.C. gathering four years ago honoring the author of "Atlas Shrugged" and "The Fountainhead." ...

At the Rand celebration he spoke at in 2005, Ryan invoked the central theme of Rand's writings when he told his audience that, "Almost every fight we are involved in here on Capitol Hill ... is a fight that usually comes down to one conflict--individualism versus collectivism."

The core of the Randian worldview, as absorbed by the modern GOP, is a belief that the natural market distribution of income is inherently moral, and the central struggle of politics is to free the successful from having the fruits of their superiority redistributed by looters and moochers. What's telling about Ryan's program is not so much that a hard-core ideologue like him would advocate it. It's that virtually the whole of the conservative movement has embraced him. (Even someone like Ross Douthat, one of the very few conservatives not implacably hostile to redistribution, has mostly praise for Ryan's plan.)

The rise of Ryan is a sign that the possibilities for bipartisan cooperation on domestic issues are, at the moment, essentially nil. This point is obscured by the figure of Ryan, a cheerful and courteous man who gives every sense of wanting to deal in good faith. But his goals, which are now fully the goals of the conservative movement and the Republican Party, are diametrically opposed to the liberal vision of capitalism shorn of its cruelest edges. His basic moral premises are foreign, even abhorrent, to liberals. He seems like a person you'd like to negotiate with, but there's nothing to negotiate over. Ryan is waging a zero sum fight over resources on behalf of the most fortunate members of society and against everybody else.