In a world with law, there are restriction on what society's most powerful can and can't do, because there are police officers, detectives, lawyers, and judges, who all work together to make sure there are consequences for crimes.
In a world without law, the only restriction on what someone with a lot of money or power can do is what they can get away with. We flirted with this territory by subjecting the rich to a very different justice system than the poor, but we are now solidly in the territory of no limits to rich people's power so long as they don't threaten other rich people.
We are now in the realm of having to consider not what is allowed to be done, but what can be done. We can no longer ask what is legal to do, only what is possible to do. It is possible for several men to ambush a person, put them in a car, put them in chains, and send them to a black site without due process. That is a thing that can physically happen in reality. That is a thing that has happened in other countries. Locking political opponents in mental institutions is a thing that can happen. While it seems unlikely that it will happen here, "intellectuals," those with the capability of challenging those in power, have been rounded up and forced to dig their own graves. Babies have been smashed against trees. That is a thing that has happened in Cambodia under the Khmer Rouge at the killing fields. That is a thing that is possible to happen. Forced labor camps are a thing that can and has happened. Mass famine as a result of disastrous government policy is a thing that can and has happened. Extermination of humans based on genetic traits is a thing that can happen.
There is no magical power that prevents these things from happening. These things happen because people make decisions to act or not act. Individuals choose to passively let bad things happen rather than put themselves at risk to say no.
Who would stop that abduction from happening with force? What if the men doing that are police officers? What if they go after your family the day after?
The constitution is just a piece of paper. Law is just an idea. For it to have any effect on physical reality, it requires someone to take actions on its behalf. Nothing on a piece of paper forces a president to follow a law. Human beings who believe in something enforce, or don't enforce, the law.
What kind of person will you be if the unthinkable starts happening?