Immigration is shaping up to be the defining political issue of the 21st century. It is a debate that just five years ago state officials wanted to ignore, preferring that details be worked out in the quiet backrooms of capitals than on public stages with widespread input. But their preferences were discounted as people in the United States, the United Kingdom, Italy, Germany, and all over the western world made it clear at the ballot box that they had a lot to say about the mass movement of people.

This pushback, expressed in the form of Donald Trump, Brexit, Matteo Salvini, the Alternative for Deutschland, and Viktor Orban, keeps kicking the already dead horse of Francis Fukuyama’s “end of history.” Far from embracing the futuristic ideal of fully transnational individuals, large numbers of people (in some countries, electoral majorities) have yelled loudly and proudly that they’re holding onto their socially unfashionable ideas of borders, nation-states, distinct cultures, and tribes.

This turn of events has made libertarians the world-over wince. Immigration is a tough issue for libertarians; it’s a political football that divides us down the middle, and where we do agree, no one will listen. Most libertarians can be fairly placed in one of two groups. The first are the “Immigration Enthusiasts” who believe the free movement of people is a natural right inherent in the non-aggression principle, who believe that immigration is an enormous economic positive from the increased supply of labor, and who believe increased cooperation, cultural understanding, and rich diversity are all positive benefits of immigration. The other camp is the “Immigration Restrictionists” who believe the utilitarian argument against mass immigration is too strong to ignore, that the added costs in social services outweighs any economic benefit, and that “diversity” leads to intranational infighting and the dissolution of social cohesion, a prerequisite for liberty.

Arguments on both sides have merit, and most importantly, they’re honest enough to debate the central question: should the state regulate or restrict movement between current state borders? Enthusiasts say no, Restrictionists say yes. But there is a third group of libertarians, who in an attempt to find a “third-way” position, end up deflecting the core problem.

These libertarians are the types who say the immigration debate is caused by the tragedy of the commons. If all the public land was privately owned, then there wouldn’t have to be this political debate because each property owner could decide for themselves who to interact with. They think that by stating the obvious, they’ve expressed a genius dipped in ideological purity, above the messy fray of sectionalism.

In reality they’ve added nothing to the conversation. Pure libertarians, both Enthusiastic and Restrictionist, agree that a fully market-based, privatized social order absent monopolized state violence (e.g. anarcho-capitalism) is the ultimate ideological goal. One side believes this would lead to free and open movement, the other side believes it would lead to very regulated movement. Whoever is correct, both would vote for the privatization of borders if it was an option.

But it is not an option. We live in a world of governments and state violence. There is no reason to believe our end goal is around the corner. This real world we live in is a world of limited options and imperfect solutions. The perfectionist mantra of “just privatize it!” hinders real progress because it removes libertarians from the debate. Murray Rothbard realized as much.

In his 1967 article “War Guilt in the Middle East,” Murray Rothbard berated libertarians who absolved themselves of having to debate ongoing political issues because of an undue sense of purity. Libertarians are great at realizing a logical, universal moral principle, “[b]ut the trouble is that the libertarian tends to stop there…” In this instance, Rothbard was talking about state responsibility for aggressive wars, but the same could be said about libertarians on immigration. Describing this “Third Camp” position, he explains:

This is a comfortable position to take because it doesn’t really alienate the partisans of either side. Both sides in any war will write this man off as a hopelessly ‘idealistic’ and out-of-it sectarian, a man who is even rather lovable because he simply parrots his ‘pure’ position without informing himself or taking sides on whatever war is raging in the world. In short, both sides will tolerate the sectarian precisely because he is irrelevant, and because his irrelevancy guarantees that he makes no impact on the course of events or on public opinion about these events.

As immigration continues to dominate politics, real decisions are being made, policies are being created and enforced, and nations are being changed. These “Third Camp” libertarians would have us opt out of the discussion. “No,” said Rothbard, “Libertarians must come to realize that parroting ultimate principles is not enough for coping with the real world.”

The same can be said for libertarians who focus on the welfare state in the immigration debate. If the problem is too many immigrants using social services, they answer the Restrictionists, then abolish the welfare state, don’t restrict immigration. This is a reasonable argument that should not be dismissed. But it is not an argument that the political world is having.

There is no serious movement to roll back the welfare state in any western country, as much as libertarians wish there were. Outside immigration hardliners, there are few in the mainstream arguing for any kind of Prop 187 measure. Neither are there ongoing arguments for a complicated sponsorship program of individual immigrants. To repeat, the only politically relevant question on the table is: should the state regulate or restrict movement between current state borders?

Immigration Enthusiasts have their answer. Immigration Restrictionists have their answer. It’s time for “Third Camp” libertarians to pick a side and join the conversation, one way or the other. As Murray Rothbard advised, “let us become relevant.”