Norman Eisen

Opinion contributor

President Trump's reckless tweeting about Special Counsel Robert Mueller's initial charging decisions is making the situation even worse for Trump, including by increasing his own personal liability.

As of Monday morning, Trump apparently thought Mueller was only going to hit former campaign chairman Paul Manafort and former campaign adviser Rick Gates for money laundering and other activity that Trump believed commenced well before the campaign and was peripheral to it. That's why Trump tweeted "NO COLLUSION!"

More:Trump offer to pay Russia probe legal bills for aides is a terrible idea

More:If you care about foreign election interference, Manafort indictments miss real threat

The president was apparently as surprised as everyone else by the George Papadopoulos guilty plea. Unsealing the plea was a smart advance move by Mueller to rebut the “no collusion” characterization of his investigation that might otherwise have taken hold by just charging Manafort and Gates. Papadopoulos’s admissions offer another, new piece of evidence of collusion. The most striking is that a foreign intermediary told Papadopoulos in April 2016 that he had just returned from Moscow and the Russians had "dirt" on Hillary in the form of thousands of emails. The plea also details Papadopoulos’s many other Russia-related contacts, and his communications about those contacts with other senior campaign officials (according to media reports, including Manafort, Corey Lewandowski and Sam Clovis).

That evidence hits hard because it goes with similar, already known evidence of collusion: the emails between Rob Goldstone and Donald Trump Jr.; the June 2016 meeting at Trump Tower between Trump Jr., Manafort and Jared Kushner and the apparent Russian emissaries; Trump's own public remarks welcoming Russian hacking of emails shortly thereafter; Roger Stone's contacts with hackers and his claims that he knew of forthcoming leaks from WikiLeaks. Can anyone doubt more evidence will follow?

Trump is rightly freaking out, and so Tuesday he pivoted to minimizing Papadopoulos and calling him a liar.

To say the least, it is very unusual for the president of the United States to attack a witness who is cooperating with the United States an ongoing federal investigation. It raises obstruction of justice and witness intimidation questions, just as it did when the president similarly went after former FBI Directory James Comey. Think about it: When you are a witness in a case that threatens the most powerful man in the world, and he attacks you publicly, that is scary.

Trump’s tweet also creates more problems for Trump with Mueller. By far the biggest personal danger to Trump is that Mueller moves against him for obstruction. That decision could go either way, but there is already substantial evidence that he obstructed justice. The reason Trump's lawyers keep talking about the White House’s efforts to cooperate with Mueller’s investigation is to convince the special counsel of Trump’s good faith, and so to limit further exposure of the president.

More:Manafort charges don't mention Donald Trump, but don't forget Robert Mueller's mission

POLICING THE USA: A look at race, justice, media

Whatever other bad things happened for Trump on Monday, at least the revelations hadn’t wiggled the obstruction needle — until Tuesday morning, when Trump attacked Mueller's cooperating witness. Take it from me as someone who for a quarter of a century worked against and with prosecutors and FBI agents (including Mueller himself): they are fiercely protective of their cooperators. By attacking Papadopoulos as a liar, Trump hardly signals his good faith to Mueller. After all, Mueller is offering Papadopoulos's testimony as true. So Trump is not just assaulting the special counsel’s cooperator; Trump is contradicting Mueller, and maybe even hinting that Mueller is intentionally offering the testimony of a liar.

That is a negative for the careful strategy of the president’s legal team, John Dowd and Ty Cobb, to cooperate with Mueller and so win his goodwill in persuading him not to take action against the president. As of today, their strategy has become harder to implement, and Mueller taking action against the president a little more likely. We have miles to go before Mueller makes his final decision of course, but for Dowd and Cobb, Tuesday's tweets might have been worse than Monday's indictments. It was too for Trump, whether or not he realizes it.

Norman Eisen, chief White House ethics lawyer for former president Barack Obama, is chairman of Citizens for Responsibility and Ethics in Washington and a senior fellow in Governance Studies at the Brookings Institution. Follow him on Twitter: @NormEisen.