Harm / care;
Fairness / reciprocity;
Ingroup / loyalty;
Authority / respect; and
Purity / sanctity.
Harm / care? Check. TSA wants us to step into a machine that will irradiate us. Sure, they say it’s perfectly safe, but not everyone agrees. And besides, this is a population that is concerned with the radiation from high-power lines.
Fairness / reciprocity? Check. TSA wants to be able to grope us, but we can’t grope them.
Authority / respect? Check. This foundation involves deference to legitimate authority. People to whom authority and respect are important (generally political “conservatives”) will defer to legitimate authority. But legitimate authority is not despotic, exploitative, or inept. (See Jonathan Haidt and Jesse Graham, When Morality Opposes Justice: Conservatives Have Moral Intuitions that Liberals may not Recognize, 2006.) When TSA is seen as having these traits, the authority / respect balance shifts, and becomes about the individual being treated with respect: these people work for us; how dare they do that?
Purity / sanctity? You betcha. You want to naked pictures of me? Of my children?
Generally, political liberals rely on the first two foundations, while political conservatives rely on all five. Before, a small number of us for whom liberty carries as much weight as any of the five moral foundations were bothered by TSA’s screening procedures. Now that TSA’s procedures have became inimical to purity and sanctity as well as health and reciprocity, the rest of America is joining the party.
All, that is, except for those who believe (for reasons beyond my ken) that the TSA’s security theatre makes us safer. They are much more inclined to submit to it, in part because of the ingroup / loyalty foundation, which supports submitting to the TSA’s procedures—if you think they work—for the good of the group.