NY Times opinion writer Farhad Manjoo says it’s time for the Democratic Party, or some brave person in it, to drag the Overton Window to the left on immigration. He believes there’s a solid case to be made for open borders and it’s time someone made it.

Imagine radically shifting our stance toward outsiders from one of suspicion to one of warm embrace. Imagine that if you passed a minimal background check, you’d be free to live, work, pay taxes and die in the United States. Imagine moving from Nigeria to Nebraska as freely as one might move from Massachusetts to Maine.

There’s a witheringly obvious moral, economic, strategic and cultural case for open borders, and we have a political opportunity to push it. As Democrats jockey for the presidency, there’s room for a brave politician to oppose President Trump’s racist immigration rhetoric not just by fighting his wall and calling for the abolishment of I.C.E. but also by making a proactive and affirmative case for the vast expansion of immigration.

He’s certainly playing up the bright side of this politically, but the actual reasoning is a bit, err, confused.

When you see the immigration system up close, you’re confronted with its bottomless unfairness. The system assumes that people born outside our borders are less deserving of basic rights than those inside. My native-born American friends did not seem to me to warrant any more dignity than my South African ones; according to this nation’s founding documents, we were all created equal. Yet by mere accident of geography, some were given freedom, and others were denied it.

It’s certainly true that where you are born has a lot to do with the freedom you’ll have in life. It’s also true that no one has control over the circumstances they are born into. You can say that’s unfair in some sense but it’s not the result of our immigration system. Contrary to the author’s claims, our system does not assume that people born abroad are “less deserving of basic rights.”

Take China as an example. If you’re born in China, you’re probably going to be poor and you’re almost certainly not going to have any say in your government or your own future. That’s tragic but it’s not the fault of the U.S. immigration system.

There’s nothing about the precepts of U.S. human rights that are limited to our border, what is limited is our sovereignty to effectuate and enforce those rights. So if North Korea, or Syria, or China is running a gulag where people are tortured, maimed or simply forced to work for free, the U.S. is against that. But we don’t have the authority on the ground to do anything about it, not unless we’re willing to fight a war against the authority that already exists in those places to establish that authority. Does Manjoo want us to do that?

Alternatively, we could short-circuit this problem by opening the borders to everyone and simply bring the people who are currently treated unfairly inside our sphere of control. Here’s just one problem with that idea. There are probably several times as many people who would rather live in America if given a choice than there are Americans. Manjoo says we have plenty of space but what happens when 40 million people (about 8.6% of the population of Central and South America) show up at the border with nothing and demand food, water, and a place to live. We’re talking about the entire population of California or double the population of New York state. How do we accommodate that? And that’s not including the 100 million or so who would probably eagerly depart China if given the chance, people who mostly don’t speak our language and don’t have much of an education.

Here’s another problem. Manjoo asks us to imagine it being easy to move from Nigeria to Nebraska. But that means it will also be really easy to move from Nairobi to New York. How does he think that’s going to work out? How long before terrorists take advantage of this to attack the nation they hate the most?

Our west coast cities are currently dealing with a serious homelessness crisis. Seattle, Portland, and San Francisco are all struggling to deal with people living on the streets, using the sidewalks as bathrooms and getting through life one fix at a time. What happens when the number of homeless people explodes to 100 times its current size in a year? I don’t think this would work out as neatly as Manjoo seems to think it would.

Ultimately, if people want the world to be fairer and more like America, they have to change the part of it where they are born to be more like America. America is happy to provide the blueprint for that if they’re interested.