Politics, like construction, has its boom and bust cycles, and fences — of both the literal and figurative sort — are out of fashion right now. We’re supposed to be erasing borders, not erecting barriers; opening hands, not clenching fists.

But while he doesn’t get much credit for it, Robert Frost’s “old-stone savage” was right: Good fences do make good neighbors. Fences differentiate what is mine from what is not-mine. Fences define the space in which I can exercise my freedom most fully. And fences keep out marauders.

Our politics is besieged by marauders at the moment. On Wednesday, Matt Nelson, the man behind WeRateDogs™, a Twitter account devoted to posting pictures of cute canines, announced that he would be donating profits from sales of select merchandise on his website to Planned Parenthood. Nelson is, of course, welcome to do with his site and his money as he wishes. What conservatives lamented was that he saw fit to politicize what had been, until then, an apolitical account.

Nelson’s left-wing followers responded differently. On his personal account, Nelson endorsed a long Twitter screed by a freelance journalist who suggested that “people literally can’t handle a person running a dog Twitter account and supporting Planned Parenthood at the same time.” Many others weighed in similarly.

This, like so many things today, is a dispute over fencing. Classically liberal politics is all about good fencing. Our system is set up to fence in the government, which the American Founders knew had a tendency to wander into adjacent territory. The persons and arrangements within the government were, themselves, fenced in further: Congress cannot do this, the president cannot do that. Politics was a crucial enterprise, but a narrow one. It was designed to do the minimal work of keeping people from killing each other — and to leave maximal space for those same people to pursue what it was never within the power of politics to provide: the various and innumerable goods that make up a human life.

In general, conservatives continue to favor this structure. Certain things are, and ought to be, outside the boundaries of politics. That’s not to say they’re not debatable, or entirely irrelevant to political considerations; it’s just to say that politics, properly understood, is a blunt instrument with little meaningful application to many, if not most, of the most meaningful parts of life.

But progressives have reversed these priorities. It is not simply that nothing is outside of politics – as an extension of the logic of “identity politics,” that is true, as far as it goes. It is that there is nothing of which the political aspects are not the most important. Mozart symphonies, Saul Bellow novels, Jivamukti yoga, Twitter accounts: The most important thing about them is how they interact with our urgent political debates.

Liberal politics was never meant to shoulder this burden, and the nastiness of our current political life makes unmistakably clear that it can’t — at least, not without turning into a deeply illiberal politics. Shoving the good things we ultimately seek — all of which transcend politics — into our local political frame is to distort both our politics and those good things.

The genius of our political order was to prioritize individual liberty, giving it as much space as possible, within the bounds of “the Laws of Nature and Nature’s God,” to seek those transcendent goods; and to make that search equally available to every person. That required fences, but those fences made for good neighbors.

It’s time to rebuild.

— Ian Tuttle is the Thomas L. Rhodes Fellow at the National Review Institute.