Special counsel Robert S. Mueller III.A close friend of Donald Trump's said the president "is considering perhaps terminating" special counsel Robert S. Mueller III, fueling speculation that has been building in Washington that Trump could intensify&nbsp;the struggle over the&nbsp;Russia&nbsp;investigation."I think he's weighing that option," Christopher Ruddy, the chief executive of Newsmax, a conservative website, told PBS' "NewsHour"&nbsp;on Monday. "I think it's pretty clear by what one of his lawyers said on television recently.""I personally think it would be a very significant mistake," Ruddy added.Ruddy's mention of&nbsp;"one of his lawyers" appeared to be a reference to Jay Sekulow, a lawyer who appeared on ABC's "This Week" program on Sunday and implied that Trump was considering the idea.Who is Christopher Ruddy, and why does he know what the president is thinking?&gt;&gt;Whether Trump has the legal authority to fire Mueller is&nbsp;untested. Justice Department regulations say that a special counsel can be fired by the attorney general "for cause."In testimony last week, responding to a question from Sen. Kamala Harris (D-Calif.), Deputy Atty. Gen. Rod Rosenstein&nbsp;implied that Mueller could not be fired directly by the president. Trump could order Rosenstein to fire Mueller. What would happen if he refused to agree is unclear.Ruddy, a longtime friend of Trump's who consults with him often, was at the White House on Monday. Sarah Huckabee&nbsp;Sanders, a White House spokeswoman, said Ruddy and Trump did not speak on Monday and Press Secretary Sean Spicer offered a separate statement."Mr. Ruddy never spoke to the president regarding this issue," Spicer said.&nbsp;"With respect to this subject, only the president or his attorneys are authorized to comment."&nbsp;Ruddy also said that Trump had initially approached Mueller about becoming FBI director after Trump fired James B. Comey last month.When Comey&nbsp;was fired, he was&nbsp;overseeing the investigation into Russian meddling into the 2016 election and potential collusion with the Trump campaign. His firing, and his Senate testimony last week that Trump requested loyalty from him and requested that he drop an investigation into former national security advisor Michael Flynn, raised significant questions about Trump's willingness to let the investigation proceed independently.Mueller previously ran the FBI and has garnered bipartisan praise.Chris Ruddy to @JudyWoodruff: President Trump is considering firing special counsel Robert Mueller, who he considered for another position. pic.twitter.com/X4IIHlh8at&mdash; PBS NewsHour (@NewsHour) June 12, 2017 Ruddy's comments came after another highly visible Trump confidant, former House Speaker Newt Gingrich, seemed to encourage&nbsp;Trump to make the move, tweeting that "Republicans are delusional if they think the special counsel is going to be fair.""Time to rethink," he added.Republicans are delusional if they think the special counsel is going to be fair. Look who he is hiring.check fec reports. Time to rethink.&mdash; Newt Gingrich (@newtgingrich) June 12, 2017 Gingrich less than a month ago had called Mueller a "superb choice: His reputation is impeccable for honesty and integrity. Media should now calm down."The public comments from close friends suggest Trump may be testing the waters on a decision that would be among the most controversial he has made since becoming president, recalling the "Saturday Night Massacre" when President Nixon fired special prosecutor Archibald Cox amid the Watergate investigation.Mueller has served multiple presidents in both parties.&nbsp;Atty. Gen. Jeff Sessions has recused himself from the investigation and is testifying Tuesday before the Senate Intelligence Committee. He is almost certain to be asked about the possibility of the president firing Mueller.