In the case of Trump, he IS one part of corporate America. He is benefiting himself and his slice of corporate America.
"Now, big corporations (the New York Times, etc.) are what stand between Trump and his agenda."
There are shades here, not as easy a statement to make as you have made.
While trump would definitely scare the American corps because of his protectionist, destabilising economic policy, the republican establishment is still behind a metric ton of the laws/bills etc that are bandied about, and they are corporate owned.
They still have the pockets of the politicians, they just don't like some of the other stuff. The weapons industry as a softball example would be jumping for joy at Trump.
So the corps are not standing between Trump and his agenda, but they definitely would have preferred a normal republican candidate.