Read it again DUI laws are not about driving. See that's the thing rights & protections otherwise afforded a person under suspicion of any other crime are not in existence if suspected of DUI.
It just truly amazes me the number of folks that are ok with lose of legal protections, rights, priveledges of others because they mistakenly think it does not & will not affect them. History is replete with examples of that not being the case.
SCOTUS has found that you have the less of an expectation of privacy while operating a motor vehicle on a public way than you do walking down the street, or sitting in your house, or operating a vehicle on a private road.
You are in the process of operating a vehicle on a public road, which is subject to traffic regulations. A road block is not singling one driver out. The police have shut down the public roadway. In order to pass with your vehicle, you must demonstrate that you are properly operating your vehicle, and are adhering to traffic codes, which includes DUI. The minute you started your vehicle up, you (the driver) are subject to inspection by law enforcement. Once reasonable suspicion that you are intoxicated is made, your vehicles becomes eligible for inspection (inventory search).
The basis of his argument is the two glasses of Merlot, as Sally sunshine who sipped gingerale all night isn't having any problems with the road block. The administration of a sobriety test is absolutely warranted on every level in that instance.
You do not have to submit to a breathalizer, however you will lose your license. Why? because you do not have a
right to that license. A driver's license is a priviledge that comes with stipulations which include subjecting yourself to random roadblocks, inspections, and yes, blowing into a machine to see if you are intoxicated. A commercial driver's license holder has to submit to drug testing/medical exam every year to maintain their license. Is that unconstitutional? Of course not.
The criminal process that plays out once DUI has been determined is the same as any other crime.
His reasoning is self-serving to the extreme, as are most Libertarian arguments. You have the right to life, liberty and the pursuit of happiness, but operating a vehicle on a public roadway is not one of them unless you adhere to rules -- as your happy hour could result in the ending of someone's life, liberty and pursuit of happiness. So that crap ain't going to fly.