A friendship between President Donald Trump and one of his formerly most vocal advocates has taken an almost-Shakespearean twist.

Anthony Scaramucci was once an ardent Trump supporter. He enjoyed a fleeting 11-day stint as the president’s White House communications director and as recently as Aug. 8 on CNBC applauded “the president’s courage for going after these issues,” referring to a yearlong Sino-American trade war.

Author William D. Cohan has described “The Mooch,” as Scaramucci is sometimes affectionately referred to (and sometimes not so affectionately), as “the most loyal friend there is” when it comes to the inner circle of the 45th commander-in-chief, in a Vanity Fair article in February of 2018.

However, all that has taken a stunning turn in less than a month, with Scaramucci’s devotion for Trump giving way to escalating enmity.

The hedge-fund manager, who looks after some $9.6 billion at SkyBridge’s fund of funds, has challenged the president’s abilities as a leader and reiterated a recent barrage of Trump criticisms in a Thursday interview with MarketWatch.

“This is an issue of mental instability and demagoguery,” he said. When asked whether Trump’s actions are substantially different than in the past, Scaramucci said he acknowledges that a lot “stuff that [Trump] is doing now is consistent” with his past actions.

“But, I don’t remember him calling himself the ‘King of Israel’ and ‘the chosen one,’” referring to Trump’s embrace this week of Newsmax TV host Wayne Allyn Root’s comments, declaring Trump the greatest president for Jews, and the president’s, perhaps joking, proclamation that he is “the chosen one” to lock horns with China over longstanding U.S. trade imbalances.

“A red line has now been crossed,” Scaramucci told MarketWatch.

“I can’t in good conscience support this man for re-election,” he said.

That notion may be all-too clear after Scaramucci wrote an op-ed in the Washington Post on Aug. 19, outlining the reasons behind his feud with the president titled: “Anthony Scaramucci: I was wrong about Trump. Here’s why.”

Check out: Scaramucci on Washington back stabbers: ‘I’m more of a front-stabbing person’

An article in Salon.com stated that the hedge-fund honcho was set to go as far as to assemble a political-action committee, or PAC, with the goal of replacing Trump as the Republican nominee for the 2020 election.

Trump has fired back several times, with his most pointed response to Scaramucci coming in an Aug. 19 tweet in which he called his former supporter “a highly unstable ‘nut job’.”

Despite the feud with Trump Sr., Scaramucci acknowledged a cozy relationship with Donald Trump Jr., for whom he hosted a dinner on July 30 at the Hunt & Fish Club near Times Square, where the hedge-fund manager is a co-owner, as reported by the Washington Examiner.

“Don and I are friends,” Scaramucci told MarketWatch.

Is there a chance, then, that Scaramucci would turn back to the Trump camp (assuming the president would have him back at this point)?

“I’ll answer that question rhetorically: Trump is 73 and the next five years his goes from 73 to 78. He’s embattled, he’s losing it mentally and I think he’s in a situation now where it is going to get worse,” he said.

So, does Scaramucci believe that his newfound war against Trump can be successful?

“The odds are long but the crazy is descending on a very aggressive downward slope,” he said of the president’s recent actions.

On Friday, Trump fired off a series of tweets, urging U.S. companies to make products domestically after China earlier in the day announced it was preparing to raise tariffs on some $75 billion in U.S. products coinciding with import duties that were set to take effect on the same date on some $300 billion in China goods.

Trump also took to Twitter to blast the Federal Reserve, perhaps perceiving a speech by Chairman Jerome Powell at a Jackson Hole symposium in Wyoming as a genuine policy-decision meeting, for not doing enough to easy monetary policy. Trump, who has frequently pressed Powell to aggressively cut interest rates, asked in a tweet, “who is our bigger enemy,” Powell or Chinese President Xi Jinping.

Trump has hitched his political success closely to the economy and the stock market, perhaps more so than any other person who has sat behind the desk in the Oval Office.

However, the escalating trade tensions could do more to unseat Trump than any efforts by Scaramucci, MarketWatch’s Jeffry Bartash writes:

“The threat to the U.S. economy from the trade dispute has been viewed as severe enough by the Federal Reserve to spur the central bank to cut already low interest rates in July. And the Fed is widely expected to cut rates again in September”

On Friday, Powell said: “Trade policy uncertainty seems to be playing a role in the global slowdown and in weak manufacturing and capital spending in the United States,” in his speech in Jackson Hole.

Wall Street appears to agree. The Dow Jones Industrial Average DJIA, +1.33% , the S&P 500 SPX, +1.59% , the Nasdaq Composite Index COMP, +2.26% and the small-cap oriented Russell 2000 index RUT, +1.59% wiped out weekly gains, skidding decisively lower after Trump’s trade-oriented tweets.

Wall Street often acts in the interest of their wallets and part of Scaramucci’s point may be that some may be willing to turn against Trump if they feel he’s not delivering on a promise of a healthy economy and booming market.