George Stephanopolous quoted the Tax Foundation as not liking the Trump tax plan. Trump said : “What do they know?” Here is the background on that foundation:
https://en.wikipedia.org/wiki/Tax_Foundation
yikes.
The interviewers want specific answers, but Trump speaks in symbols to the voters and they know exactly what he means.
For example, when he says about the Tax Foundation "what do they know?"...he's actually saying to the voters, "you know who I am and what I'm gonna do. Who the hell is the Tax Foundation?"
"They are part of the Washington problem, I am the solution."