https://www.businessinsider.com/paul-manafort-guilty-plea-cooperation-legal-implications-trump-2018-9Paul Manafort was the chairman of President Donald Trump's campaign when he offered a Russian oligarch "private briefings" on Trump's bid.
He was spearheading the campaign when WikiLeaks began dumping thousands of emails from the Democratic National Committee that had been stolen by Russian operatives.
Perhaps most importantly, he was one of three top Trump campaign officials to attend a meeting with two Russian lobbyists offering kompromat on Democratic nominee Hillary Clinton at the height of the campaign.
On Friday, Manafort pleaded guilty to two counts of conspiracy and obstruction, and Andrew Weissmann, a prosecutor working for the special counsel Robert Mueller told a federal judge that Manafort had flipped and would be cooperating "in any and all matter as to which the government deems the cooperation relevant," including "testifying fully, completely" before a grand jury.
Patrick Cotter, a former federal prosecutor who worked with Weissmann in the past, didn't mince words when he reacted to the development.
"Manafort's cooperation is the single most important advancement for the Mueller probe," he said. "He is the single most important witness thus far, because his position was such that he can shed light on the most critical question of what the president knew, and when he knew it."
Mueller is investigating Russia's interference in the 2016 election, whether members of the Trump campaign colluded with Moscow to tilt the race in his favor, and whether Trump sought to obstruct justice after the existence of the investigation became public knowledge last year.
News of Manafort's deal with Mueller came after intense speculation over whether the former Trump campaign chairman would plead guilty or go to trial.
Trump's lawyer, Rudy Giuliani, told Politico earlier this week that Manafort was in a joint defense agreement with the president, and that Trump's team was not worried about Manafort flipping.
He told BuzzFeed early Friday, less than two hours before Manafort's plea hearing, that Manafort had not withdrawn from the agreement, in what appeared to be an indication that even if Manafort entered a guilty plea, he would not be cooperating against Trump.
For that reason, Weissmann's announcement that Manafort had flipped likely "blindsided" the president's legal team, Cotter said.
But Elie Honig, a former Justice Department lawyer who prosecuted hundreds of organized crime cases, said it's common in high-profile cases for a cooperator to stay silent about their agreement with the prosecution until the last minute.
