Is there a constitutional leg to stand on here because of "interstate commerce?"
Considering the other things they've been allowed to regulate, ban, tax, and abuse in the name of "interstate commerce."
More people and goods are moved on the ground than in the air. Yet the TSA is knuckle deep in aviation transportation, assuring our "safety", feeling our wives' boobs, and looking in our children's diapers so that we can fly. Next step is border checkpoints between the states, especially into high value targets such as DC and New York. Hell, New York already has checkpoints during big events, especially travelling into tunnels and over bridges.
They took away our money to "fight poverty."
They took away our rights to be secure in our property and persons to "fight drugs".
Now, they will take away our freedom of travel to "fight terror."