If any part of liberalism needs revitalizing, it’s the case for liberalizing immigration.

Nationalists on the left and right argue that easing immigration restrictions would make Americans worse off. During the Democratic primaries, Bernie Sanders criticized open borders as a “right-wing proposal” that would “make everybody in America poorer.” And of course Donald Trump is calling for “an impenetrable physical wall on the southern border” to protect “the jobs, wages and security of the American people.” He has even floated the idea of an “ideological screening test” to ensure that the U.S. only admits those “who share our values and respect our people.” His executive orders banning citizens of six Muslim-majority countries from even setting foot in the U.S. seems to reflect this idea, and have met judicial resistance on the ironic grounds that they violate the values of the American people embodied in the constitutional guarantee of religion liberty.

Trump’s stance on immigration exemplifies a broader cultural and economic nationalism. His chief strategist, Steve Bannon, has argued that capitalism and “the underpinnings of the Judeo-Christian west” are in crisis. According to this worldview, we have to build a wall around the American economy and culture as a matter of self-preservation. Congressman Steve King expressed this view recently in a controversial tweet:

Trump, Bannon, and conservatives like King are wrong. We have overwhelming economic and cultural reasons to move toward a more open country. Indeed, some of Trump’s and Bannon’s own (professed) principles push in that direction. For instance, both tout lean government and robust capitalism. Trump says that “people flourish under a minimum government burden.” Bannon claims that “We are strong capitalists. And we believe in the benefits of capitalism. And, particularly, the harder-nosed the capitalism, the better.

Yet restrictive immigration controls empower the state to suppress market competition and dictate how people may spend their money and allocate their labor. This is the opposite of capitalism. Literally.

Immigration Restrictions Are an Attack on Economic Liberty

Small-government, hard-nosed capitalism is flatly inconsistent with outlawing the buying and selling of labor. It shouldn’t matter where the laborer is born.

For example, I’m a fan of the Philadelphia 76ers (unfortunately) and I’m eager to buy tickets to watch their rookie Ben Simmons play. And I’m sure that Simmons is equally eager to take my money. This is as capitalist as it gets: voluntary exchange for mutual benefit. Sure, Simmons is Australian, but so what? The free exchange of goods and services doesn’t suddenly become a bad idea because the provider moved across a border. Simmons plays in Philadelphia because it makes him better off, and fans pay to watch Simmons in Philadelphia because it makes them better off. That Simmons flew across an ocean to get there changes nothing of ethical or economic significance.

Restricting Immigration Hurts the Economy and Is a Bad Way to Help Poorer Workers

Maybe this is an unfair example. Simmons competes for a job with other millionaires, whereas Trump’s stated concern is immigration’s impact on poorer American workers. When immigrants enter the United States, they increase the supply of low-skilled labor and thus drive down the wages of low-skilled American workers.

I’ll note up front that the extent to which immigrants directly compete with American workers is probably oversold. Immigrants tend to have different skill sets and job preferences than native-born Americans;  as such, they tend to complement rather than displace domestic workers. For instance, low-skilled immigrants are overrepresented in construction and agricultural work and underrepresented in government, education, and social services. As you’d expect, immigrants are less familiar with local languages and customs than native-born workers, giving the latter a leg up in competitions for jobs that require these skills.  Recent studies suggest that immigration even results in a small long-term increase in the wages of native-born workers.

Still, it’s important to acknowledge the possibility that increased immigration will be bad for certain native-born American workers. In particular, those lower-skilled workers who do directly compete with immigrant labor can expect to see their wages drop by roughly 5%. But restricting immigration is the wrong way to solve this problem.

Liberal Immigration Saves Millions from Desperate Poverty

First, the benefits of liberalized immigration to the global poor are so overwhelming that it is flatly unethical to withhold them. Second, restricting immigration is a comparatively inefficient method of benefiting low-wage American workers.

Philosopher Peter Singer explains that the world’s poorest people suffer from a deprivation far graver than anything experienced by even poor Americans:

In wealthy societies, most poverty is relative. People feel poor because many of the good things they see advertised on television are beyond their budget — but they do have a television. In the United States, 97 percent of those classified by the Census Bureau as poor own a color TV. Three quarters of them own a car. Three quarters of them have air conditioning. Three quarters of them have a VCR or DVD player. All have access to health care. I am not quoting these figures in order to deny that the poor in the United States face genuine difficulties. Nevertheless, for most, these difficulties are of a different order than those of the world’s poorest people. The 1.4 billion people living in extreme poverty are poor by an absolute standard tied to the most basic human needs. They are likely to be hungry for at least part of each year. Even if they can get enough food to fill their stomachs, they will probably be malnourished because their diet lacks essential nutrients. In children, malnutrition stunts growth and can cause permanent brain damage. The poor may not be able to afford to send their children to school. Even minimal health care services are usually beyond their means.

Only one policy has been shown to effectively bring the global poor up to the living standards of the global rich: allow them to move across borders, toward economic opportunity.

The economist Michael Clemens writes, “Migrants from developing countries to the United States typically raise their real living standards by hundreds of percent, and by over 1,000 percent for the poorest people from the poorest countries. No other development policy realized within developing countries is able to generate anything close to this degree of convergence [between the earnings of people born in poor countries and those born in rich countries].”

If someone is too poor to afford enough food to avert brain damage, it is morally indefensible to deprive them of the opportunity to increase their income by over 1,000%, especially when the cost of doing so is making someone hundreds of times richer about 5% poorer. That’s like cutting in front of someone dying of thirst because you want that last bottle of Aquafina to brush your teeth.

Safety Nets Are a Better Way to Help Poorer Americans

In any case, there are better ways to protect the economic well-being of poorer Americans than restricting immigration. A free market solution to a drop in wages or employment isn’t heavy-handed regulation of the labor market. Instead, let firms compete to figure out the most efficient ways of doing business and then directly compensate those workers who are made worse off. The compensation could take the form of government safety nets like unemployment benefits or the earned income tax credit.

Trump’s first pick for labor secretary, Andy Puzder, is a fast-food executive who favors automation to keep production costs down. When McDonald’s installs automated kiosks, it worsens the labor market position of low-skilled American workers. But it also lowers the costs of a Big Mac, leaving consumers with more money to spend on other goods and services produced by other workers. Immigration has a similar economic effect. Insofar as immigration drives down production costs, Americans will have more disposable income to spend at Starbucks, where they’ll probably be served by a native-born barista with knowledge of the local language and customs.

What’s more, the economic gains from immigration can be taxed to fund the safety net for displaced workers.

Immigration Doesn’t Threaten American Values. Cultural Tests Do.

But what if liberalizing immigration kills the goose that lays the golden egg? As Bannon might put it, we have to compromise pure capitalist principles in order to save the “the underpinnings of the Judeo-Christian west” that, in his view, make capitalism possible.

One reason to be skeptical of this position is that American culture has allegedly been under siege by immigrants for decades (if not centuries), and the worry never seems to pan out.

In fact, despite Bannon’s talk of the “Judeo-Christian west,” Americans haven’t always been keen on Jewish immigration. For instance, a 1940 proposal to resettle Jewish refugees in Alaska met with resistance in Congress because of the familiar-sounding fear that “these foreigners cannot be assimilated in Alaska, and will constitute a threat to our American civilization.” And in the 19th century, “many native-born Americans regarded Catholic immigrants as an ideological and racial threat.”

Those worries were clearly unfounded. And they’re equally unfounded today. Studies of today’s immigrants find that they too tend to adopt liberal political values.

But suppose, for argument’s sake, that Bannon is right and the United States is facing a cultural crisis. There’s a bedrock moral issue at stake: how does a liberal society like the United States confront cultural and ideological challenges? Does it enlist the power of the state to forcibly exclude dissenting viewpoints or does it engage them?

Historically at least, it’s been the latter. Dissent from liberal values needn’t come from across the border. We permit Nazis to march in Illinois and the Westboro Baptist Church to picket soldiers’ funerals. These are not groups “who share our values and respect our people.” Nevertheless, they’re free to speak, protest, and assemble within our borders. A command-and-control culture is as contrary to American values as a command-and-control economy.  It’s not the state’s job to regulate away bad ideas any more than it’s the state’s job to regulate away cassette tapes and Blockbuster videos. The American way is to defeat bad ideas in what Oliver Wendell Holmes called “the competition of the market.”

Indeed, if the nationalist concern is to preserve “our values,” then I see no good reason to ignore homegrown cultural threats. If we’re going to start a program of ideological screening, why do it halfway? Let’s implement an ideological screening test for books to ensure that they contain only content that “shares our values and respects our people.” Parents influence their children’s values, so maybe you should be required to take the test before the state lets you become a parent. Presumably journalists, teachers, religious leaders, and voters will all need to be screened before they can get to work, too. After all, these people are at least as capable as immigrants of disrupting American culture.

Yet we find the prospect of these ideological screening tests chilling. A liberal society worthy of the name refuses on principle to take illiberal means to liberal ends. And this means resisting the call to use armed guards, razor wire, and religious profiling to stop peaceful people from working toward a better life in our country.

Christopher Freiman is Associate Professor of Philosophy at the College of William and Mary.