Suppose the California legislature got together and passed a law saying “Timothy Sandefur is hereby convicted of murder, and he must go to jail.” The cops come and get me and throw me in the hoosegow. Would that be due process of law?
Perhaps you say no—that would not be any process of law. That would just be going directly from law to conviction without any interceding process. If the legislature could do that, it could dispense with the court system entirely, and then all of our freedom would be at risk, because the majority could trample on the minority or the individual at any time.
Now, suppose the legislature passes a law that says “Timothy Sandefur is convicted of being a jerk, and is hereby sentenced to give up his house, or a portion of his paycheck every month.” Is that due process of law? Of course not—this is even worse, because I’m not only being convicted without any process, but I’m being convicted of something that isn’t even really a crime to begin with, so I have no opportunity to plead my case or defend myself. It’s like a “status crime”: I’m being summarily punished for who I am rather than what I did. Hardly due process of law.
Finally, imagine the law said “all libertarian lawyers are jerks and are hereby sentenced to give up a portion of their paychecks every month.” This would be still worse, right? Not only is there no hearing and no opportunity for us to make our case, and not only are we being convicted of a crime that isn’t a crime, but now it’s a whole class of people, despite all the differences between them, being lumped together for no good reason, and just being summarily exploited.
If you agree with that, then congratulations—you agree with the principles of substantive due process articulated by the Lochner Court. As I explained in my post, “What Is Substantive Due Process, Really?” the concept is not the monster that you have been led to believe. It is a simple rule that says that if you are going to be punished—if you’re going to have your life, liberty, or property taken away—it has to be for some legitimate public reason, and not just because the legislature decided it. If the mere fact that the legislature decided it was enough to constitute due process, then there would be nothing wrong with the three hypothetical laws I’ve described above. The due process clause has “substance” because might does not make right—that is, the mere fact that the majority voted in favor of exercising political force does not make that exercise of political force a law. Law, to be law, must be a rule that benefits the public in some way.
If you actually read Lochner, you’ll see it makes a lot of sense. The law in that case deprived bakers of the liberty to work overtime—something very important to poor people trying to make a living. Such a law only constitutes due process, therefore, if the reasons for that deprivation are legitimate public reasons—not just because the legislature decided so, or because depriving them of liberty would increase the wealth or pleasure of some politically powerful group. A law summarily depriving me of a portion of my paycheck merely for who I am—or a law summarily depriving bakers of the right to earn a living for no good reason—violates the Fourteenth Amendment. That is what Lochner says. And I think it’s right.
Other types of regulations do the same thing as the three hypothetical laws I’ve mentioned. Take a law regulating the rates that railroads may charge. Such a law says “railroad companies are jerks, therefore they are going to be deprived of a portion of their paycheck every month.” Take a law that forbids blacks and whites from intermarrying. Such a law says “blacks are jerks, therefore they are going to be deprived of their right to marry whom they wish.” There are any number of these sorts of laws. Nineteenth Century courts called these types of laws “class legislation,” because they deprived people of their liberty or property simply because they belonged to a certain class—usually the upper class—for the benefit of some other class.
Now, perhaps you do not agree that Lochner and these other cases were rightly decided. But (1) you must at least admit that there is a sensible argument here, and (2) you must explain how, or whether, in your view, the hypothetical laws I’ve mentioned would be illegitimate.