President Donald Trump's spate of attacks against witnesses in the Russia investigation, like the former White House counsel Don McGahn, could open him up to new charges of obstruction and witness tampering, according to legal experts.

Legal experts say he is especially vulnerable because those charges can be brought after he leaves office, as the special counsel Robert Mueller emphasized in his report.

"It's baffling that the president would continue doing a lot of the same things that, at least in part, landed him in this mess in the first place," one former senior DOJ official told INSIDER.

Trump's continued attacks against McGahn and others could also contribute to a growing appetite for impeachment in the Democratic-led House of Representatives.

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President Donald Trump has made no secret in recent days of his fury toward the special counsel Robert Mueller's final report in the Russia investigation, which the Justice Department released last week with light redactions.

In addition to accusing "highly conflicted" Mueller and his team of "18 Angry Democrats" of going on a fishing expedition, the president also took aim at Democratic lawmakers investigating him and former senior Justice Department and FBI officials who launched the Russia probe.

Crucially, Trump also targeted people like the former White House counsel Donald McGahn, who painted a portrait in Mueller's report of a frustrated president who tried multiple times to thwart Mueller's sprawling investigation.

Trump lashed out at McGahn after the report was released, telling the public to "watch out" for him and accusing him of fabricating his testimony to prosecutors.

Read more: 'Total bulls---': Trump takes aim at former White House counsel Don McGahn while ripping into the Mueller report

Justice Department veterans say the comments may open the president up to new charges of obstruction and witness tampering.

"It is a federal crime to retaliate against a witness — meaning to take some specific action to harm a person (firing, for example) in connection with or as payback for the person's prior testimony or statement to law enforcement," Elie Honig, a former federal prosecutor from the Southern District of New York, told INSIDER.

"It is also a crime to tamper with a witness — if the efforts at intimidation can be seen as efforts to influence or prevent testimony in the future by the parties being attacked or by others," Honig added.

This isn't the first time the president and his lawyers have launched public attacks aimed at witnesses who testified against Trump.

Michael Cohen. AP Photo/Julie Jacobson

Read more: Mueller revealed why he didn't charge Trump with obstruction, and it directly contradicts what AG Barr told the public

As Michael Cohen, Trump's former lawyer and fixer, was gearing up to testify before three congressional committees about the president's conduct in February, Trump and Giuliani suggested investigators should in turn target Cohen's father-in-law.

Cohen subsequently postponed his testimony, citing "ongoing threats" against his family by the president.

McGahn, meanwhile, put out a rare statement through his attorney after Trump and Giuliani attacked his credibility, saying the incidents of potential obstruction of justice that he relayed to Mueller's team "are accurately described in the report."

"This is risky," William Jeffress, a Washington criminal defense lawyer who represented President Richard Nixon after he left the White House, told Politico of Trump's attacks against McGahn. "I find it surprising because he's taking these shots at witnesses who gave information to Mueller, and I think he's got to be careful because there's an explicit federal statute punishing retaliation against witnesses."

Robert Mueller. AP Photo/J. Scott Applewhite

'Trump has a glass jaw'

A 1973 decision by the Justice Department's Office of Legal Counsel said a sitting president cannot be indicted. In his report, Mueller cited that decision as one of the reasons he declined to "make a traditional prosecutorial judgment" on whether Trump obstructed justice.

But the special counsel laid out a detailed roadmap of evidence prosecutors had collected in the obstruction probe. After outlining 11 potential instances of obstruction of justice, Mueller's team wrote, "If we had confidence after a thorough investigation of the facts that the President clearly did not commit obstruction of justice, we would so state. Based on the facts and the applicable legal standards, however, we are unable to reach that judgment."

Read more: Mueller referred 14 criminal matters to other prosecutors, but only 2 of them are public so far

The report also pointed out that a president can be criminally prosecuted after leaving office. And it highlighted Congress' power to investigate potential wrongdoing by the chief executive.

One former senior Justice Department official who worked closely with Mueller when he was at the FBI told INSIDER the special counsel "is as meticulous as they come in choosing his words."

"He would not have included those statements in the report if he didn't think there was evidence of potentially criminal conduct," this person added. "It's baffling that the president would continue doing a lot of the same things that, at least in part, landed him in this mess in the first place."

Barbara McQuade, a former federal prosecutor from the Eastern District of Michigan, told INSIDER Trump's efforts to prevent witnesses from testifying or retaliating against them "could be obstruction of justice, but no more likely to be charged criminally than the instances that appear in the Mueller report."

Read more: Mueller says Trump was unsuccessful in influencing the Russia investigation — but mostly because his aides didn't follow orders

Jeffrey Cramer, a longtime former federal prosecutor in Chicago who spent 12 years at the Justice Department, offered a different view.

It's "impossible to prove witness tampering by a guy who constantly insults everyone who crosses him," Cramer told INSIDER. "Trump is unique in that his normal discourse is attacking those who say anything against his interest. He has a glass jaw."

Prosecutors and juries "react to evidence that shows acts that are a departure from someone's normal course to demonstrate witness tampering and the like," he added. "The simple fact is that 99% of the population don't spend their day criticizing others. Our President resides in the remaining 1%, so it would be a difficult criminal case to pursue."

U.S. President Trump speaks at the Rx Drug Abuse & Heroin Summit in Atlanta, Georgia Reuters

'Witness tampering in plain view'

But the president could face other obstacles, particularly from a newly empowered, Democratic-led House of Representatives.

Since the Mueller report came out, the Democratic response has fallen into one of two camps.

Some of the more progressive members of Congress, like New York Rep. Alexandria Ocasio-Cortez and Sens. Elizabeth Warren and Kamala Harris, are pushing to impeach the president.

Read more: House Democrats subpoena the full Mueller report and its underlying evidence

But establishment Democrats, like House Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer, are pumping the brakes on impeachment while they demand an un-redacted version of the Mueller report, arguing that Congress needs all the facts before moving forward.

House Judiciary Committee chairman Jerry Nadler has also said he wants more information before opening impeachment proceedings. To that effect, in addition to subpoenaing the full Mueller report, his committee also recently subpoenaed McGahn to testify before the panel.

Continued attacks by the president on his former White House counsel and other witnesses would "certainly make it more likely" for the House to impeach Trump, a Democratic aide on the House Judiciary panel, which would be in charge of formally launching the proceedings, told INSIDER. "That would be witness tampering in plain view."