By Noah Bierman and Brian Bennett

Tribune Washington Bureau

WASHINGTON, D.C. — President Donald Trump returned from a brief Twitter hiatus Thursday to call himself the victim of “the single greatest witch hunt of a politician in American history!” illustrating his anger over the appointment of a special counsel to head the investigation of Russian interference in last year’s election.

His tweets undercut the more measured official statement that the White House had issued the night before and illustrated the degree to which the investigation may distract and damage his presidency.

Trump went on to lament that his predecessor, President Barack Obama, and electoral opponent, Hillary Clinton, were not similarly investigated by a special counsel.

“With all of the illegal acts that took place in the Clinton campaign & Obama Administration, there was never a special councel appointed!” he wrote, misspelling “counsel.” Trump did not specify what he meant by illegal acts.

The appointment of Robert Mueller III, the former head of the FBI, as a special counsel to head the Russia investigation was announced late Wednesday. Deputy Attorney General Rod J. Rosenstein made the appointment because Attorney General Jeff Sessions has stepped aside from involvement in the case. He did not inform the White House about the appointment until after it had been made.

Trump had been relatively quiet on Twitter over the prior two days, issuing only a handful of official announcements about meeting with a foreign leader, and delivering a commencement speech.

The White House statement Wednesday night offered muted approval of the investigation, urging a speedy conclusion.

But Thursday morning’s tweets indicate that Trump will handle the news of a special counsel the way Trump handles all controversies — with a vigorous and potentially self-destructive fight.

Other presidents have faced similar investigations — at times raging behind the scenes — but none had a Twitter account that made their moments of self-pity and anger so public.

The tactic carries great risk. It may unite Trump’s core supporters — a group that had begun showing some signs of wavering even before the latest batch of news, polls indicated.

Trump has frequently attacked the news media and Democrats, groups that are unpopular with his supporters, as a way of solidifying his backing.

But Mueller is a much tougher target — a former prosecutor and FBI chief who is highly respected by members of both parties in Congress.

Attacking him could alienate Republican leaders in Washington and elsewhere. Trump badly needs their support during a crucial stage when many are weighing how and if to come to his defense and remain publicly behind him.

The more Trump displays his impulsive and angry side, the harder it may be to rally that support.

Moreover, unlike other enemies Trump has railed against — even some within his own party — Mueller will be harder to defeat in a pure political or public relations context. Even if Trump’s voters dislike him, he will have the power to compel testimony and demand documents as long as he remains on the job.

As a special counsel, Mueller could be fired by Trump, much as Richard Nixon fired Watergate special prosecutor Archibald Cox. As that example illustrates, however, firing Mueller almost surely would escalate Trump’s political problems, not solve them.

Rep. Elijah Cummings of Maryland, the top Democrat on the House Oversight Committee, underscored that with Mueller’s appointment, the investigation will now move into a new, potentially less partisan phase that could be much more damaging to Trump.

At this point, the various congressional committee probes should “take a back seat” to avoid interfering with Mueller’s work, he said on MSNBC’s “Morning Joe.” He added that he hoped Mueller would meet with the leaders of the various committees “and make sure that we don’t step on his investigation.”

Trump plans to leave the country Friday for a nine-day trip that now promises to be even more fraught for the new president. Before he leaves Washington, he is scheduled to appear at a joint news conference with President Juan Manuel Santos of Colombia Thursday afternoon.

The session will be the first time Trump may be questioned in a public forum since a series of controversies that began with the firing of FBI Director James B. Comey last week.

Comey was in the midst of leading the Russia investigation, and Trump’s abrupt dismissal of him is likely what prompted Rosenstein to appoint Mueller to restore a sense of independence to the investigation. Mueller and Comey were close allies when both served in the George W. Bush administration — Mueller as FBI chief and Comey as deputy attorney general.

In an interview last week on NBC, Trump said he had the Russia investigation on his mind when he fired Comey, although he also said he did not mean to interfere with the investigation.

The next major event was the news that Trump had asked Comey during a meeting in the Oval Office to drop the investigation of Michael T. Flynn, Trump’s former national security adviser. Comey wrote a confidential memo about Trump’s request shortly after the meeting, according to Comey associates who have read the memo and described it to reporters.

Wednesday night, The New York Times reported that Flynn warned the Trump administration weeks before he started his White House job that he was under FBI investigation for work he had done on behalf of Turkey’s government during the campaign. Flynn did not register as a foreign agent until recently, a possible violation of federal law.

But Trump’s problems do not end on the home front. He will also face potential skepticism from allies he meets on his trip to Saudi Arabia, Israel, Belgium and Italy.

“The problem is all this stuff here at home is going to follow him overseas,” said Sen. Lindsey Graham, a South Carolina Republican. “My advice to him is to just stay disciplined, stay focused, and deliver on the world stage.”

The week offered a preview of how the distractions for the White House, combined with Trump’s disdain for scripted protocols, could leave the president ill-prepared for his debut abroad.

On Tuesday, Trump repeatedly mispronounced the name of Turkish President Recep Tayyip Erdogan as Erdogan stood beside him. He also appeared bored or distracted when Erdogan spoke, coming to life when the Turkish president injected some fulsome praise for Trump and his election victory.

Over the last two weeks, Trump’s official schedule was relatively light as aides made time for him to cram on geopolitics for a trip that will take him from the complexities of the Middle East to summit meetings with skeptical-to-hostile leaders in Europe.

Presidents usually sit through “pre-trip briefings galore” before foreign visits, said Michael Allen, who was an advisor to President George W. Bush.

Before Bush traveled, his White House chief of staff would carve out extensive time for senior directors on the National Security Council and other experts to tutor the president. Allen said the briefings could get quite precise: “this is what you will see, what they will say, what you might discuss, what you need to know.”

But with Trump, said a Republican who formerly worked in the White House, “the trouble will be if he goes off script. Trump can’t control himself.”

At the same time, the official said, everywhere “he will be treated to respect and pageantry. Trump will eat of lot of that up.”