Impeachment: Trump abuses power by harassing, intimidating witnesses like Yovanovitch Trump has a pattern of public witness tampering. Using his presidential platform this way may not be criminal but that is not relevant to impeachment.

Mimi Rocah and Jennifer Rodgers | Opinion contributors

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It was a shocking moment in Marie Yovanovitch's public testimony to Congress on Friday, but it shouldn't have been.

The former U.S. ambassador to Ukraine was discussing an April phone call she had received in the middle of the night from a State Department official telling her that she was being recalled from her post, and that she should immediately return to Washington because of concerns about her “security.” Yovanovitch said she later learned the reason for her recall was a smear campaign orchestrated by Rudy Giuliani and others because she was standing in the way of their corrupt agenda in Ukraine.

As she spoke, President Donald Trump was on Twitter doing exactly the same thing to Yovanovitch that his cohorts had done: attempting to smear and intimidate her.

A pattern of public witness tampering

“Everywhere Marie Yovanovitch went turned bad," he wrote less than an hour after the Friday hearing began. "She started off in Somalia, how did that go? Then fast forward to Ukraine, where the new Ukrainian President spoke unfavorably about her in my second phone call with him.”

That July 25 call was when Trump told Ukrainian President Volodymyr Zelensky that Yovanovitch was “bad news,” and that “she's going to go through some things.” Yovanovitch testified that when she read the call summary, she was so "devastated" that "the color drained from my face" and that she had a "physical reaction."

Trump ended his Friday tweet with, "It is a U.S. President’s absolute right to appoint ambassadors."

House Intelligence Committee Chairman Adam Schiff read Trump's tweet to Yovanovitch during her live testimony and asked for her reaction. Viewers saw in real time as she responded, with admirable restraint, that it was “very intimidating.”

As dramatic as it may seem that the president effectively interrupted a witness’ testimony to attack her as she spoke, this was not his first foray into public witness tampering. It is, in fact, one of his go-to moves:

►About 4 a.m. on Feb. 27, the morning Trump’s former lawyer-fixer Michael Cohen was set to testify before Congress, Trump tweeted that Cohen “was just disbarred by the State Supreme Court for lying & fraud. He did bad things unrelated to Trump. He is lying in order to reduce his prison time.”

►And just days before Cohen was subpoenaed to testify, Trump tweeted threatening comments suggesting that Cohen’s father-in-law should be investigated.

►Trump tweeted disparaging remarks ("Never a big fan!") about former White House counsel Don McGahn at a time when congressional Democrats were actively seeking McGahn’s testimony about special counsel Robert Mueller's report, which highlighted his testimony as implicating Trump in multiple counts of obstruction of justice.

Trump and some of his supporters defend these tweets attacking and vilifying witnesses against him by claiming that the president has the right to express his opinion. But the right to express one’s opinion does not extend to criminal speech, such as verbal efforts to intimidate or tamper with witnesses. And the language, the pattern, the timing and the contrast with tweets about other potential witnesses whom Trump considers loyal makes clear what he intends by these smear attacks.

Abuse of power is enough: You don't have to break a law to be impeached. Trump's defenders need a better argument.

Take Roger Stone, who kept Trump’s support even through his criminal conviction Friday for lying to Congress and intimidating a witness. Trump claimed that Stone, who worked on GOP campaigns stretching back to Richard Nixon's, was the victim of a “double standard” in a tweet after the guilty verdict. Last year, the president praised Stone after his arrest for declaring that he “will never testify against Trump.” He then attacked the prosecutor in the Stone case as “rogue and out of control” and tweeted, “Nice to know that some people still have ‘guts!’ ”

Similarly, the day after his former campaign manager Paul Manafort was convicted of multiple federal felonies (and when he would be most vulnerable to deciding to cooperate), Trump tweeted his support: "Such respect for a brave man!"

Impeachment isn't a criminal matter

Federal witness tampering law, which is part of a broader obstruction of justice statute, makes it a felony to try to dissuade or hinder witnesses from attending or testifying in an official proceeding. Intentional harassment of a person to dissuade them from testifying is a separate felony.

As a legal matter, do Trump’s actions rise to the level of witness intimidation or harassment under the federal statutes? Such a case would come down to whether a prosecutor could prove that Trump’s intent in sending the tweet was to intimidate or harass Yovanovitch and/or other witnesses in the impeachment inquiry against him.

Downside of Watergate: We found crimes. Now people think that's what it takes to impeach a president.

Given the ongoing pattern of conduct that Trump has demonstrated, it’s possible. The targeted attacks by the president on witnesses who may provide damaging testimony against him are designed to discredit their testimony, to deter them from cooperating and to cause other witnesses to think twice before coming forward, lest they receive the same treatment. Especially when contrasted with the praise for witnesses who have chosen not to cooperate against him.

Critically, though, impeachment is not a criminal matter, and so these federal statutes, including their strict intent requirements, are irrelevant here. The real issue for these impeachment proceedings is whether Trump appears to be using his platform and the power of the presidency to intimidate and harass witnesses who are providing highly damaging testimony against him. The answer to that is clearly yes.

Mimi Rocah, a former federal prosecutor, is Pace University law school's Distinguished Fellow in Criminal Justice and an MSNBC/NBC News legal analyst. Jennifer Rodgers, also a former federal prosecutor, is a lecturer at Columbia Law School and a CNN legal analyst. Follow them on Twitter: @Mimirocah1 and @JenGRodgers