I think the difference with DUI checkpoints/searches is fairly easy to illustrate:

DUI: You are checking drivers on an evening and in a location where it is likely, based on statistics, and prior results, that you will find DUI violations, and make the world safer that evening.

TSA: You are virtual-strip-searching or frisking children, elderly, and other non-suspicious Americans, randomly, or based on the "hotty" factor for women, without any basis in statistics, prior results, etc..

In the DUI situation, you have a strong probability of catching someone, a reason for suspicion that on Friday night down the road from Joe's Roadhouse's all night happy hour...

In the TSA situation, there's essentially zero probability and historical precedent for catching a terrorist by scoping or frisking ordinary American travelers, especially 6 year olds, etc..

I think if they go that route, they'll lose in court.

I could see on a case by case basis, if there was "terrorist chatter" of an incident on a particular day, or airport, of increased security to search EVERYONE... that would actually seem a little more reasonable.

But what they are doing now are involuntary searches without any suspicion whatsoever. We had a right to travel without these searches before, and the government is now denying our ability to freely exercise that right without subjecting to a search.

It's like the landlord situation, because they can still own and live in the rental property, they just can't get their "rental license" without complying with the search, which means if they rent without the license, they are punished, which means loss of liberty or property (i.e. fines).

In our case, it is the same, if we try to fly without consenting to the search, we will be arrested, fined, etc.. Meanwhile, the traveler in front of us, and behind us, are "randomly" allowed through the metal detector and don't have to consent to anything to exercise their right.

Which seems another issue, like equal protection. Without probable cause, what gives TSA agents the right to choose who gets to keep their constitutional rights and freedoms?