Surprise Michael Cohen guilty plea signals something big may be brewing in Mueller probe In the 18 months that special counsel Robert Mueller has been probing Russian meddling in the 2016 U.S. presidential election, there has been one, big Watergate-style question hanging over Washington. What does he know and when will he show it? The events of the past few days suggest a two-part answer — quite a bit, and very soon. Robert Mueller, seen in this 2008 file photo, has been investigating allegations of Russian meddling in the 2016 presidential election. (Alex Wong/Getty Images) This morning in Manhattan, Donald Trump's former lawyer Michael Cohen made a surprise appearance in U.S. District Court to plead guilty to a new charge of making false statements to Congress. Cohen, who is cooperating with Mueller's office, had already copped to several crimes in Trump's service. They include: Making a $130,000 US hush-money payment to porn actress Stormy Daniels. Arranging for a friendly tabloid publisher to buy and bury the story of an ex-Playboy model who also claimed to have had an affair with the man who is now U.S. president. Both actions count as illegal campaign contributions, and Cohen faces four to five years in jail. But today's plea goes to the heart of what Mueller has been probing over the past year-and-a-half — whether Trump had undisclosed ties to the Russian government, and whether his campaign colluded with the Kremlin to boost his chances in the 2016 vote. The nine-page charge sheet details how Cohen "misled" two U.S. Congressional committees when he claimed that a planned Trump real estate venture in Moscow fell apart at the very beginning of the campaign in January 2016. It also indicates he lied when he said he never succeeded in making contact with Vladimir Putin's office. Cohen now admits that discussions carried on into June 2016, and that the Russian President's office did respond to his request for help in securing land and financing for the project; a gaudy, glass tower that would soar above every building in Moscow and have Trump's name at the very top. He also reveals that plans were afoot to send Trump to Russia mid-campaign to hammer out a deal and perhaps meet with Putin. Some of this simply confirms what was already reported in the Washington Post a year ago, and fleshed out in a Buzzfeed investigation this past spring. However, Mueller now appears to have a witness who will testify that the president lied when he claimed that he had no business dealings in Russia and that discussions about the project ended at a very preliminary stage. That shouldn't come as a shock, given that Trump has dissembled and deceived more than 3,800 times in the two years since the election. Yet paired with some other recent developments, it suggests that Mueller is rapidly building both collusion and obstruction of justice cases against the U.S. president. Last week, Jerome Corsi, a right-wing conspiracy theorist and political gadfly, shared a document that Mueller's office had prepared as part of possible deal for his testimony. The draft suggested that Trump might have had prior warning of Wikileaks' October 2016 dump of Hillary Clinton campaign emails — stolen by Russian hackers — via Corsi's communications with his longtime friend and advisor Roger Stone. And then on Monday, it emerged that Mueller's cooperation deal with Trump's former campaign manager Paul Manafort has unravelled because he reportedly lied and breached his plea agreement.