Note that I said to re-read my post, not the Constitution...
Executive orders? I realize they aren't part of the Constitution, but they have superseded it. I mean, some of FDR's programs and measures (including #9066) were essentially beyond the reach of the necessary and proper clause, yet they were done through executive order. And if Martial Law is declared, if I'm not mistaken, "all bets are off," so to speak.
Either way, given the previous terrorist attacks, and also the overwhelming predisposition of certain ethnicities and countries of origin connected to terror, I'd say that's probable cause, at least in the case of airport security. I'm not saying a secret police. Not even illegal search and seizure. There is no right to travel, and therefore, I would think that airport security would certainly be subject to different measures than, for example, a typical traffic stop.
FDR's programs did not violate the Bill of Rights or the XIV Amendment.
Your application of probable cause is also misplaced. To apply probable cause to racial profiling you have to establish that there is a probability or likelihood that each individual within the subject class is involved in planning to do harm. The fact that the September 11 hijackings were carried out by Arabs or Muslims does not make it probable that the 25 year old Arab graduate student getting on a plane in Kansas City is a terrorist.
And there is a Constitutional right to travel, guaranteed by the Interstate Commerce Clause. In fact, this right was critical in the Civil Rights movement as it was used to strike down racially discriminatory practices of restaurants and hotels because it inhibited the ability of Blacks to travel if they could not be provided food or lodging.
