The bombshell news from this week, including the guilty plea of former personal lawyer of President Donald Trump, Michael Cohen, and the conviction of the president’s former campaign chairman, Paul Manafort, made the impeachment threat more real than ever. That was compounded by the reports at the end of the end of the week that Trump confidantes AMI Chairman David Pecker and Trump Organization CFO Allen Weisselberg had received immunity deals from prosecutors investigating the Cohen case.

People close to the president, including current and former White House aides, acknowledged that Tuesday was one of the darkest days of Trump’s year and a half in office.

“The verdict in the Manafort trial isn’t nearly as worrisome to me as the Cohen agreement and the Cohen statement,” said former Trump adviser Michael Caputo told Politico. “It’s probably the worst thing so far in this whole investigation stage of the presidency.”

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Republicans close to the White House worried that Cohen – with his access to Trump’s history of business dealings and troubling personal entanglements – could prove more damaging to Trump, and give Democrats material for impeachment if they take the House in November.

Nancy Pelosi, the House minority leader, issued a firm statement on Tuesday criticizing Trump, but she did not mention impeachment.

A source close to Trump said, “I must admit a bit of concern about what he [Trump] would do fully backed into a corner,” Axios reported. Maggie Haberman, White House correspondent for the New York Times, tweeted on Tuesday that “this has moved to a different stage.”

Presidential historian Jon Meacham told MSNBC, “This is rather like the third week of June, 1973, when [former White House counsel] John Dean went to the Senate and began his testimony [before the Watergate committee]. It’s the kind of moment that you can begin to see a genuine inflection point.”