Imagine a debate about legalizing marijuana. One participant admits that “I am for legal marijuana. I am only against the illegal kind.” Most people will easily see that he eludes the subject: the crux of the matter is whether existing laws prohibiting the sale and possession of marijuana should be liberalized or perhaps abolished altogether.
With that in mind, imagine a racial segregation debate around 1960. One participant says: “I am for the legal integration. But I am against the illegal kind.” Again, it is evident that the person who said this is missing the point. The question was whether existing segregation laws should be abolished (or at least severely restricted). If she wants to argue that segregation laws are fine in some states (those that had them at the time) but are wrong in others (those that didn’t), she needs to provide an explanation of why segregation is right and fair is locations but wrong elsewhere.
The same applies to almost any other context where there is a debate about the liberalization of laws that restrict certain activities. Anyone who follows such questions realizes that “I am for legal X” is a workaround for the real problem that is not driving the discussion.
The big exception is immigration policy. There we routinely hear variants of “I am for legal immigration, but against the illegal kind.” And many see this as a serious argument.
In reality, it is no more valid than similar statements related to segregation, war on drugs, or anything else. The discussion about immigration policy is about whether different types of immigration should be legal. The statement “I am for legal immigration” does nothing to answer this question.
If the idea is that you support current legal immigration but oppose one that is currently illegal, you need to explain how and why the status quo policy draws the right line – much like the person doing it Supported segregation in some states but not in others The example given above needed to explain what the difference is between the two types of conditions. The “I support legal immigration” mantra does not refute the arguments that current immigration restrictions are unfair, cause enormous economic damage, and endanger the freedom of locals and potential immigrants.
If the claim here is that people have a moral duty to obey immigration restrictions until they are properly lifted by Congress, it is still not an answer to the claim that some or all of those restrictions should be removed. The greater the obligation to obey even unjust and harmful laws, the greater the moral need to repeal such laws as quickly as possible.
Even on its own terms, the duty to obey theory has to contend with arguments that many immigration restrictions are so severely unfair that migrants are not required to obey them. This challenge is especially difficult to face if, like many Americans, you accept the idea that it is perfectly okay to routinely disregard a variety of less onerous laws like speed limits and various minor economic regulations. Regardless of this, the question of whether people are obliged to obey a certain law is conceptually separate from the question of whether this law should exist at all. Most debates on immigration policy actually deal with the latter issue.
If your objection to the current illegal immigration is that it undermines respect for the rule of law, this is a good justification for legalization! That would solve the problem far more thoroughly than cracking would be possible. If you think illegal immigration undermines the rule of law in a way that most of us routinely do (most adult Americans have broken federal criminal law at some point in their lives), you need to explain what it means what makes immigration law special.
Eventually, if you really support all of currently legal immigration and only oppose the illegal kind, you should oppose efforts by Donald Trump and a few other Republicans to severely curtail current legal immigration. If you are indifferent to such plans or actually support them, you are not in favor of currently legal immigration. They are in favor of cutting it massively and you should defend that position.
There are many intellectually serious arguments in favor of restricting immigration, including some for bringing it below current levels. In my recent book, Free to Move: Foot Polling, Migration, and Political Freedom, I address a variety of such claims. But the trope “I am for legal immigration” is not a serious contribution to the discussion. The sooner we can withdraw it, the sooner we can focus on the real issues at stake in debates over immigration policy.