John Brennan, who was CIA director at the time, then started to notice that the Russians were reaching out to Trump campaign officials. His “radar” went off. Here's what he told Congress in a hearing about Russian meddling on Tuesday. It's worth reading the whole paragraph, but I've bolded some key points:
“Having been involved in many counterintelligence cases in the past, I know what the Russians try to do. They try to suborn individuals, and they try to get individuals, including U.S. persons, to try to act on their behalf, either wittingly or unwittingly. And I was worried by a number of contacts that the Russians had with U.S. persons. And so therefore, by the time I left office on January 20, I had unresolved questions in my mind as to whether or not the Russians had been successful in getting U.S. persons involved in the campaign or not to work on their behalf, again, either in a witting or unwitting fashion. And so, therefore, I felt as though the FBI investigation was certainly well-founded and needed to look into those issues.”
In other words: When the Russians want to spy or meddle in other nation's affairs, their go-to move is to find people from that nation to cuddle up with — or to blackmail, if it gets to that. (“Suborn” sits right in the middle of those two. It means to bribe or secretly convince someone to do something.)
When the director of the CIA realized that the Russians wanted to influence the U.S. election, he knew to keep an eye out for Russians reaching out to people tied to the election. And sure enough, Brennan said, Russian officials started holding meetings with members of the Trump campaign.
Michael Flynn. Kushner. Now-Attorney General Jeff Sessions. They all met with Russian officials at some point, and CNN and the New York Times, respectively, have reported that Sessions and Kushner did not disclose their meetings with Russians on their security-clearance forms. A security clearance is required before a person can be privy to the nation's top secrets. Other members of Trump's campaign already had deep ties to Russia, among them former campaign manager Paul Manafort and adviser Carter Page.
And it's fair to say that U.S. investigators would have been very intrigued to see then-candidate Trump's son-in-law, one of his closest advisers, receiving meetings with Russians. This is a member of Trump's inner circle, as close as you can get without meeting with the candidate himself. Not to mention that Kushner is family. Going back to April 2016, we know Kushner met at least twice with the Russian ambassador to the United States, Sergey Kislyak, and a Moscow banker.
That's not to say meeting with the Russians equates to colluding with the Russians.
Brennan emphasized to the House Intelligence Committee: “These are contacts that might have been totally, totally innocent and benign as well as those that might have succumbed somehow to those Russian efforts.”
“Many times they know that individuals may be Russian officials,” he said later, speaking broadly about how Russians use people, “but they don't know that there is an intelligence connection or an intelligence motive behind it.”
Brennan made clear that he had only suspected that Russians may have used or tried to use members of the Trump campaign to influence the election.
But — and this is a really key but — his suspicions were enough to refer everything he knew to the FBI.
The FBI, we know now, took Brennan's concerns seriously. The agency is waist-deep in a months-long, mostly covert investigation of Russia meddling and whether the Trump campaign helped. And its investigation has led it to the highest ranks of the White House.
Exactly what investigators want to know from Kushner (whose lawyer said he will cooperate) isn't clear. But why their investigation has led them to Kushner is clearer.
Given what we know about how the Russians try to use people, it makes sense that Kushner, who had several meetings with high-level Russians and is one of the president's closest advisers, is part of this investigation.