BASED on what stirs passions and wins headlines, it would be easy to imagine that the only cultural debates that matter in America are the ones that have to do with sex.

There are good reasons for our intimate obsession: Desire is intertwined with identity, sex conceives the human future, the family is the place where all our ladders start. But to understand America’s changing cultural landscape, sometimes a wider lens is useful — because the same trends that have altered the way we think about sex and reproduction have wider repercussions as well.

Consider two issues: casino gambling and marijuana. We’re used to the idea that attitudes on a controversy like gay marriage have changed with unprecedented speed. But both casinos and pot have gone mainstream over the last generation at a similarly remarkable pace.

In 1990, casino gambling was still concentrated in Nevada and Atlantic City. Then came the rise of Indian-reservation gambling; then came casinos with no tribal fig leaf. Today 23 states have commercial casinos, and the old model of casino-going as a what-happens-in-Vegas excursion has given way to casino-going as routine entertainment.

Ross Douthat

Josh Haner / The New York Times

“In the Northeast and mid-Atlantic states,” a report from the Institute for American Values noted this year, “nearly every adult now lives within a short drive of a casino.” And after this Tuesday, that drive may get considerably shorter, because New York voters are expected to ratify a constitutional amendment allowing up to seven more casinos in the state.

The marijuana revolution is arguably not so far advanced, since only two states, Washington and Colorado, are experimenting with outright legalization. But more such experiments are expected to follow soon, and medicinal marijuana is already available in 20 states. Meanwhile, public opinion on the issue has shifted about as fast as it has on gay marriage — from 32 percent support for legalization in 2002 to 58 percent in the latest Gallup poll.

There are significant differences in the ways gambling and pot have won America. The spread of casinos has been more of a top-down phenomenon, driven by states seeking revenue and an industry that’s free with campaign contributions. The permissive turn on marijuana has been a more (if you will) grass-roots affair — driven by activists and artists, influenced by empathy for the terminally ill, and hastened by public exhaustion with the drug war.

But both have been made possible by the same trend in American attitudes: the rise of a live-and-let-live social libertarianism, the weakening influence of both religious conservatism and liberal communitarianism, the growing suspicion of moralism in public policy.

And both, in different ways, illustrate the potential problems facing a culture pervaded by what the late sociologist Robert Bellah called “expressive individualism” and allergic to any restrictions on what individuals choose to do.

This is clearer in the case of casinos, whose consequences for the common good are straightforwardly disastrous. As the Institute for American Values report points out, the alliance of state governments and gambling interests is essentially exploitative, and the tax revenue casinos supply comes at the expense of long-term social welfare. Casinos tend to lower property values and weaken social capital in the places where they’re planted, they’re more likely to extract dollars from distressed communities than to spur economic development, and their presence is a disaster for the reckless and the addiction-prone.

Pot is a more complicated issue, given its essential harmlessness for many users and the crying need to lock up fewer Americans for nonviolent offenses. But one can support decriminalizing marijuana possession, as many states have done, while still doubting the prudence of legalizing (and, of course, taxing) its open manufacture and sale.

Whatever benefits legalization brings with it, it will almost certainly increase marijuana use, which has already risen sharply in the last decade. And as purely recreational as a joint may be for casual tokers, steady use isn’t always so harmless: it can limit educational attainment, and with it economic mobility, to an extent that mirrors the impact of growing up in a single-parent home.

Perhaps these costs are just the price we pay for liberty, in the same way that certain social liberals and libertarians regard the costs of family breakdown as a price worth paying for emancipation from sexual repression.

But liberals especially, given their anxieties about inequality, should be attuned to the way that some liberties can grease the skids for exploitation, with a revenue-hungry state partnering with the private sector to profiteer off human weakness.

This is one reason previous societies made distinctions between liberty and license that we have become loath to draw — because what seems like a harmless pleasure to the comfortable can devastate the poor and weak.

Or else, with pot and slots no less than bread and circuses, it can simply distract their minds, dull their senses and make them easier to rule.

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