Sen. Sheldon Whitehouse (D-RI), ranking member of the Senate Judiciary subcommittee investigating Russian interference in the 2016 election, on Tuesday said Donald Trump Jr.’s emails arranging a meeting with a Kremlin-linked lawyer “clearly show intent to collude.”

“This email chain, and particularly connecting in both Manafort and Kushner, shows clearly an intent by the leadership of the Trump campaign to try to collude with Russians to get opposition research,” Whitehouse said on CNN.

Trump Jr. on Tuesday morning published his email exchange with Trump family acquaintance Rob Goldstone, who told him a “Russian government attorney” could give Trump Jr. alleged compromising information on Hillary Clinton as as “part of Russia and its government’s support for Mr. Trump.”

Whitehouse said there is “a good case to be made” that opposition research is “actually a thing of value under the American campaign finance laws, which makes this a potential conspiracy to violate the campaign finance laws’ prohibition on receiving a thing of value from a foreign government.”

“It clearly shows intent to collude. Going in, they knew that this was Russian information, that a Russian attorney was flying over to deliver it, that it was intended for political purposes, that the campaign was going to be involved,” he said. “They even talked about the timing of it, that it would be better to come out later in the summer, presumably closer to the election.”

Trump Jr. on Tuesday night offered his first defense of his decision to hold the meeting: He wanted to “play it out.”