[Schmedlap]

"What I get out of that is that you think the government has the right and duty in question not because of the harm an impaired driver actually does, but because of the harm an impaired drive might do, the risk, the potential violation of rights."

No. That is not what I think or what I wrote. That is why the government does, but not why it can.

To summarize from my last post, the government can exercise the right and duty in question for the following reason:

"Because you, I, and all other citizens own public property, we can create a deliberative body to establish ground rules for behavior on our property and a body to objectively enforce those ground rules."

The government does act in the way that it does for the following reason:

"Our society has found that this activity is likely to impair the driver’s ability to safely operate a vehicle. We see this as an unnecessary risk that is worth banning, because of the likelihood of doing harm to other drivers, causing an accident that disrupts traffic, does harm to property, etc."

[KrisKrinkle]

No. That is not what I think or what I wrote. That is why the government does, but not why it can

But that's what I asked. My question was Why does the government have this right and duty... I don't recall asking why the government can although I might have somewhere in this mess. And I did not ask why the goverment "does act this way."

It still sounds like you are saying the government has a right and duty to arrest someone because that someone poses a risk (might cause harm) to another. That's a scary thought as a standalone. And you did add "unnecessary."

By that same logic, you might say our society has found that people under the influence of certain drugs are more likely to harm others in some way, that the risk of this harm is unnecesary, and that the governemnt has a right and duty to make the drugs illegal and arrest the people who use them.

Consider the meanings and relationships of does, can and should.