Was working on a research paper when I came across this from "The Fearful and the Frustrated" in The New Yorker:

"

Trump gave a tight, concerned nod. “There’s great danger with the illegals, and we were just discussing that. But we have a tremendous danger along the border, with the illegals coming in.”

“Have you seen any evidence here to confirm your fears about Mexico sending its criminals across the border?”

Another grave nod. “Yes, I have, and I’ve heard it, and I’ve heard it from a lot of different people.”

“What evidence, specifically, have you seen?”

“We’ll be showing you the evidence.”

“When?”

He let that one pass.

"

Feels like Trump was alluding to what we're beginning to understand here, hence why he cited evidence he wasn't willing to provide at the time.

https:// www. newyorker.com/magazine/2015/08/31/the-fearful-and-the-frustrated