I am aware of that.
Good. (But then why bring it up?)
But your justification implied that Congress may indeed regulate intrastate activity if that intrastate activity interfered with the free flow of interstate commerce.
How is a quotation from the decision you brought up "my justification"?
Are you saying now that Congress may not do this? That states are free to impede interstate commerce, and Congress is impotent?
I'll think on that. In the meantime, I'll reiterate that the Shreveport decision doesn't support your position.
I should have said, "I am aware that is your claim".
"In the meantime, I'll reiterate that the Shreveport decision doesn't support your position."
It does in the sense that the USSC ruled that Congress may regulate intrastate commerce if it substantially affects their interstate regulatory efforts. In this case, it was to negate the advantage that one carrier had over the others, thereby impeding competition.
The bottom line? It brought intrastate commerce into Congressional regulatory play. That you cannot deny, and that's what makes the case significant.