The Fourth Amendment says:
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated.
Key word: "unreasonable". Are the searches at issue unreasonable under the circumstances?
Maybe they are, maybe they aren't - but the inclusion of the word "unreasonable" means that the desperately wanted absolutism doesn't exist.
Moreover, air traffic is under the purview of federal regulation because it involves transporting people and things in interstate commerce. In fact, it's almost definitionally interstate - that is largely the point of air travel, to move something from one state to another. Its activities almost exlcusively cross state borders.
Nothing new here - it's the same kind of jurisdictional coverage maritime ports got before planes were invented.
And to think that air travel - given its national security implications - has to be left to the initiatives of individual states is laughable. Are we going to let New York have a different policy for checking bags and people for security than Iowa, and both of them different from California? Are we going to have 50 different airport protocols? Are we going to have one state where you take off not have something illegal to carry in air transit (say, a Bowie knife) but the state where you land make it a criminal offense to have on you?
What is it with libertarians being so immune to common sense?
And last I checked, Texas was still bound by the Supremacy Clause. Thus, unless they can challenge the law as facially unconstitutional and win, they are bound by it. Nullification is a fantasy.