Look at the polls, and Donald Trump is crushing his Republican opponents. But from the perspective of Sam Nunberg, a political adviser who worked for Trump until earlier this year, The Donald’s campaign is losing—and is just a couple months from total disaster.

“What I’m worried about is, I don’t know what his inner circle is telling him. I hope they’re being honest. I’m more worried, I’m not optimistic,” Nunberg told The Daily Beast. “Under the scenario that I’m laying out, I do not think that he will win… This is what I would say from a ‘glass half-empty’ perspective if I were talking to Mr. Trump.”

To be sure, predictions of Trump’s demise have so far proven wrong—he has defied conventional wisdom, and continues to be the frontrunner in the Republican presidential primary despite controversies that would have eliminated almost any other candidate. But the trajectory of the campaign thus far, Nunberg says, means that it is more likely than not that Trump will lose the first presidential contests in Iowa and New Hampshire, then hobble into South Carolina having lost frontrunner status and ceded momentum to his competitors.

Falling poll numbers in the first key states, a lack so far of reserved advertising, a low net favorability and underperformance in the college-educated voting bloc that dominates the early presidential contests—all these contribute to a darkening forecast for the Trump campaign, Nunberg argued.

Nunberg began consulting for Trump as early as 2011, and became a full-time adviser in Trump’s office in 2014. But Nunberg was fired over the summer due to a series of racist Facebook rants, including one 2009 post in which he called the president a “Socialist Marxist Islamo Fascist Nazi Appeaser.” So he is not exactly an impartial observer, despite his protestations to the contrary.

Apparently Trump doesn’t see eye to eye with his former aide. In characteristic Trump fashion, the businessman struck back against Nunberg’s analysis in a biting, personal way.

“Sam Nunberg was fired. He’s a highly self-destructive individual who makes routine calls begging for his job back. This is the interview of a desperate person who is trying to hang on and stay relevant,” Trump told The Daily Beast.

Nunberg maintains that he’s a staunch supporter of Trump’s candidacy, and took great pains during our interview to stress his personal esteem for the businessman. The purpose of speaking out, he said, was to create an “open memo” in which Trump might be alerted to his campaign’s shortcomings.

“Given the time I’ve devoted to him over the years, I’d like to see him at least get the nomination,” Nunberg said. “I like Mr. Trump, I worked for him for a long time, and consider myself close to him. He’s one of the few people I’ve ever worked for that I have a close personal affinity for.”

But despite his affection for the candidate, Nunberg insists that no one should be sanguine about Trump’s prospects. “He’s not going to win in Iowa, and he is very precarious in New Hampshire,” Nunberg said.

First, to Iowa. Nunberg says Trump has a natural disadvantage among caucus-goers in the state: a majority of caucus-goers hold college degrees, a demographic which tends not to support Donald Trump. Combined with a net favorability of +17 percent, compared to Sen. Ted Cruz’s net favorability of +55 percent, Trump has very little room to grow.

And while the Trump team might argue that they can win based on bringing newcomers into the Iowa caucus process, there has been no dramatic increase in the number of registered Iowa voters. With just over a month until caucus day, the number of registered Republicans in Iowa (PDF) is roughly what it was on caucus day in 2012 (PDF), Nunberg said—meaning that while there has been an increase, it hasn’t been nearly large enough to back the Trump campaign’s argument.

“Mr. Trump’s real ceiling is going to be 20 percent on caucus day,” Nunberg predicted, based on what he called a “pessimistic” view of the facts. He pointed to three live surveys of likely Republican voters, conducted by Monmouth, Loras, and the Des Moines Register in December, that show Trump losing to Cruz.

“He’s going to lose Iowa. Cruz will win Iowa,” Nunberg said. “Some of that Trump support will move over to Cruz in New Hampshire, once he loses. I then believe that, because Rubio will… consolidate a lot of that establishment support… he’ll surge at the end.”

Like in Iowa, a majority of 2012 New Hampshire primary voters have college degrees, a state where Trump is currently leading. But a recent poll said that 57 percent of voters in the state would “never” vote for Trump in a primary.

And recently, Trump has also gone to war with Union Leader, a prominent New Hampshire newspaper. In an editorial, the Union Leader compared Trump to “Biff,” a character from Back to the Future. Trump responded by calling the newspaper’s publisher a “lowlife.”

Nunberg also cited a USA Today/Suffolk University poll in November that had Trump at 22 percent in New Hampshire, which dropped to 15 percent if Mitt Romney was added to the list of candidates. Despite those strong numbers, Nunberg said this indicated that Trump’s support in New Hampshire was more a function of his name identification than genuine support.

While former Gov. Jeb Bush and his super PAC have reserved more than $14 million in New Hampshire and Boston commercials, including two Super Bowl ads, while Trump is somewhat late to the party, finally insisting Tuesday that he’d spend millions on TV ads in early contests. Meanwhile, Rubio and his super PAC have planned for over $6 million in commercials in New Hampshire and Boston in the weeks leading up to the primary.

“Once he loses Iowa, he’ll drop” in New Hampshire, especially if he doesn’t come through with significant television advertising, Nunberg said. “Everybody else is buying TV right now, so it’s an advantage everyone else has over him, regardless of whether he thinks he needs it or not. They will be using TV to cut into his support.”

If Trump loses Iowa and New Hampshire, he’ll stumble into South Carolina. “Once Cruz wins Iowa, and if he beats Trump in New Hampshire, which he very well could, Cruz would win South Carolina, from a momentum perspective,” Nunberg predicted.

If this scenario plays out, Nunberg doesn’t “see a pathway to the nomination—he certainly wouldn’t be the frontrunner anymore, and his numbers will start to fall.”

Nunberg said he hoped that Trump’s inner circle of advisers were informing the businessman of the trajectory their campaign was on. And while he’s not sure the campaign would be doing any better if he had remained on board, he said he viewed failure as an outcome that was more likely than not.

“I hope that Mr. Trump would be able to see a pessimistic scenario, and that his inner circle is letting him know of this pessimistic scenario,” Nunberg said. “This is what I’d be worried about, this what I’m playing out.”

Despite having been fired months ago, Nunberg still always calls the businessman “Mr. Trump,” a verbal quirk of those who work or have worked for him.

“I have respect for him. I would never call him Donald,” Nunberg said.

Updated 12:04pm 12/30/15 to add comment from Donald Trump.