The early immigration laws, such as the Chinese Exclusion Act of 1882 and the Immigration Act of 1924, were intended to “to preserve the ideal of U.S. homogeneity.” That is, they were openly racist and aimed at limiting the immigration of non-whites. Immigration was revised in 1952 and then again in 1965. The 1965 Immigration and Nationality Act changed the quota system and removed many of the racial barriers that had marked immigration since the 1920s.
As social norms changed after the 1960s, open racism became largely unacceptable. As such, openly justifying immigration and border control policy based on race became problematic. As such, the narrative changed from preserving the homogeneity of the United States against the threat of non-whites to the narratives of protecting American jobs and protecting Americans from crimes. After 9/11 a new narrative was added, that of protecting Americans from terrorists.
The election of Donald Trump saw the narrative pushed back into the past—while the mainstream narrative is still focused on crime and economics, white nationalists openly express their fears that they will be replaced by non-whites. Sometimes this is dressed up as concerns about culture, but often the white nationalists are honest in their racism.
While those ignorant of history might mistake this as something new in American politics, it is a return to the old roots of immigration and border policies. Some would even argue that the core of these polices has never not been racist, that the racism has merely been obscured in varying degrees.
It might be objected that while racism might have been a factor in the past, it does not influence current immigration and border policy—the chants and YouTube videos of the white nationalists notwithstanding. After all, some might contend, those pushing for stronger border control and tighter restrictions on immigration argue that their goals are to reduce crime and to protect the American economy. Put simply, the argument is that they are not being racist because they are trying to address the real problem of crime and the economic threats posed by migrants. It is just a coincidence that these polices also tend to impact and target non-whites. For this to be true, there would either need to be real problems that would be best addressed with these policies or those supporting the policies would need to believe that these problems are real and are best addressed with these policies. Since it is difficult to determine what people do or not sincerely believe, I will focus on the reality of the situation.
While the narrative of the criminal migrant has long been pushed, the facts present a rather different picture. Migrants are less likely to commit crimes and more likely to be victims of crimes relative to people born in the United States. It is, obviously, true that migrants do commit some crimes. As such, it can be argued that reducing the number of migrants would reduce the number of crimes and thus such policies are warranted on the grounds of fighting crime. This would, however, be a rather odd approach to take since the general principle behind it would be that methods of reducing the size of the population would be justified based on reducing the number of crimes. Interestingly, this principle would nicely justify public policies supporting birth control and abortion—fewer people would entail fewer crimes. It could also justify population control in the form of legal restrictions on the number of children: if people have fewer children, then there will be less crime. My point is, obviously, not to argue for population control but to contend that restricting migration to reduce crime makes no more sense than imposing family size limits in order to reduce crime. While both approaches would reduce crime, they are hardly an effective or sensible way to address crime. It would be more effective to use social resources to directly address crime and its causes.
The idea that migrants will steal jobs is also an old one yet is generally unfounded. Overall, migrants are generally beneficial to the economy. Naturally, migration is not purely beneficial—there are negative economic consequences for those who might lose their jobs to migrants. However, having people come here to steal their jobs is not the biggest threat American workers face. It is far more likely that their jobs will be lost to automation, offshoring or changes in the economy. For example, coal workers have suffered not because of migrants taking their jobs, but because natural gas and renewable sources of energy are making coal increasingly obsolete as a source of power. Ironically, efforts made to help the economy by restricting migration would thus seem more likely to harm it.
Given that the crime and economic arguments used to justify migration and border policy fail, then there seem to be few explanations left. One is, of course, that those making these arguments believe what they are claiming—which would entail that they either have secret information they are not sharing with anyone else or simply refuse to accept the evidence that is available. A second explanation is that the crime and economic arguments are mere covers for their real reasons. While speculating about true motivations is problematic, the most plausible explanation is that they desire to continue the old policies that are based on race. After all, if they had a good alternative argument backed by facts, then they would simply use that and there would be no need to lie.