“You always take those meetings because you never know when someone will come in with something that’s a game changer, especially with this campaign that didn’t have a research operation,” said one former Trump campaign adviser still in touch with the White House who, like several others interviewed for this report, spoke on the condition of anonymity to talk candidly. “They were so desperate for research that they would meet with anyone.”…

“Paul Manafort should have stopped this,” said one former Trump campaign official, but he didn’t want to anger Trump Jr. because “he was about to ascend.”…

But according to multiple former campaign officials and observers, Trump’s children knew very little about how campaigns were supposed to respond to offers from foreign, adversarial governments.

“I worked on a campaign in 2007 and 2008, and I was the Russia adviser to President Obama and we vetted these kinds of meetings very closely, precisely to avoid even the appearance of something like this,” said Michael McFaul, a former U.S. ambassador to Russia. “That was my experience, that was my job. I’m not sure who did this for the Trump campaign, but that was my job.”