In the National Review, Avik Roy writes that everyone is missing the point of the conservative reformers. The changes aren't happening, or aren't mainly happening, at the level of policy. They're happening at the level of principle. "Where many reformers differ from their ancestors is in the philosophical source of their support for free markets," he writes.

"The older, libertarian-flecked strain of American economic conservatism appreciates liberty as an end in itself," he writes. But the new conservatives see it differently. "For many of today’s conservative reformers, equality of opportunity — especially for the poor — is the highest moral and political priority."

When people in this town begin talking principles instead of policies, watch out. (PAUL J. RICHARDS - AFP/GETTY IMAGES)

Whenever people turn a discussion of policy into a discussion of principle, it's wise to check your pockets. Principles matter, of course. But they're also the vehicle in which motivated reasoning has the easiest time taking the wheel. A single principle can easily be used to justify starkly opposite policies.

Take equality of opportunity. Everyone in American life professes to believe in equality of opportunity. But nobody really believes in it. Equality of opportunity is often set in opposition to equality of outcome. Communists believe in equality of outcome. Capitalists believe in equality of opportunity.

In truth, equality of opportunity and equality of outcome aren't opposites. They're partners. Companions. Inseparable amigos. You can't have real equality of opportunity without equality of outcome. A rich parent can purchase test prep a poor parent can't. A rich parent can usher their children into social networks a poor parent can't. A rich parent can make donations to Harvard that a poor parent can't.

The inequalities of the parents always and everywhere become the inequalities of the children. As Theodore Dalrymple has written, "true equality of opportunity is unachievable - or could only be achieved through a level of social engineering that would make North Korea look like a paradise of laissez-faire."

When people say they believe in "equality of opportunity," they really mean they believe in "sufficiency of opportunity." They don't believe all children should start from the same place. But they believe all children should start from a good enough place. They believe they should have decent nutrition and functioning schools and a safe community and loving parents. They believe they should have a chance.

The question is what they're willing to do about that belief. Democrats who believe in sufficiency of opportunity tend to want to spend more on health care and education for the poor. They believe that making pre-kindergarten universal will help close the gap on an important inequity in early childhood. They believe that the less children or their parents need to worry about staying afloat, the more they'll be free to work to get ahead.

On the Republican side, Rep. Paul Ryan (Wis.) has taken the lead in arguing that conservatives should focus on opportunity. But his approach largely consists of cuts to the safety net. The policies enshrined in his budget suggest that the poor are held back by the government spending too much money to cover the uninsured and too much money on food stamps and too much money on education and too much money on childhood nutrition and too much money on daycare.

These are not policies required by the finances of government. Ryan also holds taxes low, cuts tax rates, and increases defense spending. Rather, they're required by Ryan's theory of opportunity, which is that a key problem for the poor is the transformation of "our social safety net into a hammock, which lulls able-bodied people into lives of complacency and dependency." His budget reflects this theory. According to the Center on Budget and Policy Priorities, almost two-thirds of his cuts come from programs that serve the poor.

Rep. Paul Ryan's (R 2013 budget tries to boost opportunity by cutting programs for the poor.)

Helping the poor by cutting the programs they rely on is, to say the least, a risky theory of uplift. It's easier to see what Ryan's plan does to impede sufficiency of opportunity than to spread it. “Ryan’s plan is a privatization of the prerequisites for opportunity,” Jacob Hacker, author of “Winner-Take-All Politics, told me. "They become the province of people whose parents have made it.”

The tension between Ryan's policies and his rhetoric is underscored by the simple fact that not one of them represents a break with the older form of libertarian-flecked conservatism. Those conservatives also supported block granting Medicaid and cutting food stamps and flattening the tax code and voucherizing education.

Roy largely admits this. In the end, he indicates that the difference here is more messaging than it is substance. "It is of considerable importance that conservative reformers emphasize opportunity, especially for the poor and the lower-middle-class," he says. "It may not lead these reformers to disagree with other conservatives on specific policy remedies, but it does lead reformers to elevate a certain portion of the conservative policy menu to the fore."

This is why it's wise to keep debates about principle grounded in actual policies. Changing principles requires little more than changing rhetoric. It's the policy where you can see if anything is actually different -- if there are new risks being taken or theories being tried or problems being addressed. Someone who has changed their message from liberty to opportunity but hasn't changed their policies really hasn't changed much of anything at all.