Updated at 9:55 a.m. ET on June 15

President Trump dismissed a potential obstruction of justice investigation into his conduct, calling allegations of collusion between him, his campaign or people associated with him and Russia a "phony story."

Of course, it's possible to obstruct justice without colluding.

Trump was responding to a Washington Post report that special counsel Robert Mueller, who is overseeing the Department of Justice Russia investigation, is looking into whether Trump attempted to obstruct justice. An hour later, Trump was back at it, calling the investigation the "single greatest WITCH HUNT in American political history." (People who followed McCarthyism closely might disagree.)

The president also appeared to undermine Mueller's leadership, saying the "witch hunt" was being "led by some very bad and conflicted people!"

There has been an effort on the right to try to undermine Mueller to de-legitimize his potential findings...:

... even though some of the same people just a month earlier had been praising the former FBI director for his esteem:

News of Mueller looking into potential obstruction comes after former FBI Director James Comey testified last week. He said he didn't know if Trump obstructed justice, but said it was for Mueller to decide.

Comey testified that he told the president he was not personally under investigation three times and confirmed that Trump was not under investigation at the time of his firing on May 9.

But, "Officials say that changed shortly after Comey's firing," the Post reports.

It stands to reason that the circumstances surrounding Comey's firing would now be at the center of Mueller's query. That's particularly the case since other high-ranking administration officials have declined under oath in open testimony to provide more details about whether Trump asked them in any way to influence Comey or the investigation.

Director of National Intelligence Dan Coats, National Security Agency Director Adm. Mike Rogers and Rogers' former deputy, Richard Ledgett, agreed to be interviewed as part of Mueller's investigation, according to five people "briefed on the requests" who were "not authorized to discuss the matter publicly," the paper reports.

Officially, Mueller spokesman Peter Carr told NPR's Carrie Johnson, "We'll decline to comment."

NSA spokeswoman Vanee Vines told NPR's Phil Ewing, "NSA will fully cooperate with the special counsel. We are not in a position to comment further."

A spokesman for Trump's personal lawyer in the Russia matter, Marc Kasowitz, said, "The FBI leak of information regarding the president is outrageous, inexcusable and illegal."

Comey's firing is a "central moment that's being looked at" in the investigation, Post reporter Devlin Barrett told NPR's Ari Shapiro on All Things Considered, "but it's not the only thing." Investigators are also considering the conversations Comey and the president had leading up to that point.

In his testimony on June 8, Comey told the Senate Intelligence Committee that he believed Trump had fired him over his role as lead of the FBI investigation into Russian interference in the U.S. election and Trump campaign associates' possible ties to Russia.

The White House has been inconsistent with its public messaging about the dismissal — initially saying Trump took the recommendations of Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein about Comey's management of the FBI and his handling of the Clinton email investigation. But then the president himself said he had made up his mind prior to receiving the recommendations from the two top lawyers at the Department of Justice.

Comey testified that initial explanations that he was fired because of poor leadership were "lies, plain and simple." He also said Trump had privately urged him to pull back on the investigation into former national security adviser Michael Flynn — a claim that the president has denied. Comey said he declined to tell agents working on the case about his conversation with Trump to shield them.

The Washington Post previously reported that Trump also asked Rogers and Coats to push back against the FBI's investigation. The intelligence chiefs declined to discuss their private conversations with Trump during a Senate panel hearing on June 7.

Asked whether Trump's actions rose to the level of obstruction of justice, Comey testified last week: "I don't know. That's Bob Mueller's job to sort that out." But Comey did lay out facts that a prosecutor could use to try to prove obstruction.

Trump and his supporters cast Comey's testimony that he had told the president he was not personally under investigation as vindication. Trump disputed, though, Comey's assertion he had asked for a pledge of loyalty. After Comey's much-watched Senate testimony, the president said in a press conference that he would testify under oath regarding his interactions and conversations with the former FBI director.

"I think, frankly, our story shows that the president is by no means out of the woods as far as the investigation goes," the Post's Barrett told NPR.

Chatter surfaced earlier this week that the president was considering firing Mueller. After a day of speculation, White House spokeswoman Sarah Huckabee Sanders said, "While the president has the right to, he has no intention to do so." The New York Times reported that Trump had been waved off the idea by advisers.

Deputy Attorney General Rosenstein, who appointed Mueller on May 17, testified on Tuesday that he would not fire the special counsel without "good cause."

Trump is not the only one under scrutiny, Barrett said: Investigators are also looking into the finances of Trump associates.

"Oftentimes what happens, frankly, in counterintelligence investigations is you start looking at sort of a core intelligence question — What did the Russians do and did they do it with any Americans? — and it grows into: What did any of those Americans do in their financial matters that may also raise alarms with the FBI?" Barrett said.

Mueller's investigative team has expanded in recent weeks. The National Law Journal reported on June 9 that Mueller has brought Deputy Solicitor General Michael Dreeben onto the team on a part-time basis. Reporter Tony Mauro noted the addition of Dreeben may signal that "Mueller may be seeking advice on complex areas of criminal law, including what constitutes obstruction of justice." At the end of May, the chief of the Justice Department's Fraud Section, Andrew Weissman, also joined the team, NPR's Carrie Johnson reported at the time.

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