The isn’t strictly about TPA. If Boehner and McConnell had a record of acting like an opposition, or if Obama didn’t ignore limits on Executive power, there would have been some grumbling, but this TPA would have passed without huge fanfare.
That said, here’s a more detailed explanation and history of the Constitutional issues in trade agreements:
http://constitution.findlaw.com/article2/annotation12.html
My post spoke to the constitutionality of TPA.
TPA has existed since the 1930s.
Ed Meese is the greatest AG in a century.
I trust his and Ted Cruz judgment.