https://www.dailykos.com/stories/2018/4/19/1758452/-Manafort-was-under-investigation-because-Mueller-suspected-he-was-Trump-s-back-channel-to-Russia
"Previously, the special counsel had clarified that Paul Manafort’s connections to Russia weren’t just historical, but active during the Trump campaign. During Kilimnik’s time working for Manafort in Kiev, he had served as a liaison for Manafort to the Russian aluminum magnate Oleg Deripaska, with whom Manafort had done business. Emails previously described to The Post show that Manafort asked Kilimnik during the campaign to offer Deripaska “private briefings” about Trump’s effort. According to the filings, “Person A,” who is assumed to be Kilimnik, had multiple communications with Manafort and his partner Rick Gates during the campaign. These communications were not about events in Ukraine several years ago. They were about what Manafort was doing at the time. They were about the Trump campaign. Manafort’s role in the campaign wasn’t as coffee boy, and he wasn’t a distant adviser that Trump can easily disown. Paul Manafort was Donald Trump’s campaign manager for a critical part of the campaign. He was actively exchanging information with Russian officials"