NBC's top entertainment executive, Robert Greenblatt, slammed Donald Trump in August on Facebook as "toxic" and "demented," describing a "sad state of affairs thanks to a pompous businessman turned reality TV star."

The private Facebook social media post — which did not mention Trump by name but was confirmed to be referring to him — was quickly taken down.

Two months later, TV actor Alec Baldwin began mercilessly satirizing Trump on NBC's Saturday Night Live. And an 11-year-old video tape of lewd banter between Trump and Billy Bush, then of Access Hollywood, also an NBC property, surfaced in the Washington Post. It aided Hillary Clinton in the critical days before a pivotal debate.

The leaker has not been identified, a spokesperson for NBC's parent, Comcast Corp., said last week.

Trump apologized for the vulgar comments on the archival NBC tape, but the episode nearly sank his campaign. In a speech two weeks later in Pennsylvania, Trump took special aim at Comcast, suggesting that its 2011 acquisition of NBCUniversal concentrated too much media power in "one massive entity" and that if elected, he would look into breaking it up. Trump also said at the time that he opposed an $85.4 billion proposed merger of telecom giant AT&T/DirecTV and media conglomerate Time Warner Inc., which owns CNN.

Trump again focused his anger at CNN in a press conference last week, calling it a purveyer of "fake news." At the same time, Trump blasted online-news site Buzzfeed — in which Comcast-owned NBCUniversal has invested $400 million — a "failing pile of garbage" for posting online unverified documents about him.

On Jan. 20, Trump will be sworn into office as the nation's 45th president, a day that should be a triumph for Comcast and NBC, the television network that made Trump a high-grossing TV  star through The Apprentice reality series and other business dealings.

But the once-tight NBC/Trump relationship has soured spectacularly. Among the already mentioned grievances, Trump believes that NBC, CNN, and other mainstream outlets failed to treat him fairly during the election campaign. He has taken to Twitter to bash Baldwin's skits as "one-sided" and label NBC News as "terrible."

A Comcast spokesperson said last week that the company looks forward to working constructively with the Trump administration and noted that it has invested billions of dollars into the U.S. economy in recent years.

Today it seems anyone's guess at the Comcast Center in Center City, or at NBC's 30 Rock offices in Manhattan, what will happen in a potentially unfriendly administration with a new president who can harbor personal grudges — as evidenced recently by his tweeting attacks on former Fox News anchor Megyn Kelly, now with none other than  NBC News.

At the same time, though, Trump has loaded his new political team with policy advisers who espouse fewer regulations and faster economic growth, leading observers to think that Trump won't intervene in big business — potentially leaving Comcast/NBC with a public relations problem under Trump and not a business one.

The merger-driven Comcast is expected to acquire significant companies over the next four — and potentially eight — years of a Trump administration, if history holds. And those deals many times require federal regulatory approval.

"Despite some of [Trump's] populist rhetoric on the campaign trail that suggests he is against media monopolies and a trust-buster, the people who are guiding his transition teams and his policy positions do not seem to hold the same ideas," said Victor Pickard, associate professor at the Annenberg School for Communication at the University of Pennsylvania.

Throughout the campaign, Trump "was picking fights with media organizations and journalists who offended him," said Pickard. "But I think it's wrong to assume that such posturing will translate into aggressive measures against media concentration."

If Trump has a "beef with NBC, that may cause some PR problems," said Andrew Jay Schwartzman, a telecom lawyer in Washington. But he added, "this is going to be a deregulatory administration that will be good for all the cable companies, including Comcast."

Indeed, Comcast, whose CEO Brian Roberts golfed with President Obama and is considered supportive of Democrats and Hillary Clinton, now faces the prospect of a president with multiple grievances against the company.

Trump's transition team did not respond to emails. But it's safe to say that the relationship between the president-elect and Philadelphia's biggest corporation has been strained for many months: besides Greenblatt's Facebook post, the Access Hollywood tape and Baldwin's SNL skits, there are the issues of NBC's firing Trump in 2015 over his comments on Mexican immigrants and his diminished role in The Celebrity Apprentice, now hosted by actor and former California Gov. Arnold Schwarzenegger.

It's a raw topic still, given Trump's tweet on Jan. 6 after the latest Celebrity Apprentice show: "wow, the ratings are in and Arnold Schwarzenegger got 'swamped' (or destroyed)." In a personal dig at the onetime Terminator, Trump added  "so much for being a movie star—and that was season 1 compared to season 14. Now compare him to my season 1. But who cares, he supported Kasich & Hillary."

Since his victory in November, Trump has been actively courting conservative news outlets, hiring Stephen Bannon of Breitbart News for a top political job in Washington.

Trump also has reportedly asked media baron Rupert Murdoch, who controls 20th Century Fox, owner of the conservative Fox News cable channel, for names of individuals who could head the Federal Communications Commission. The FCC regulates TV stations as well as wireless and cable companies. Democrat and Obama confidant Tom Wheeler has said he will step down this month.

"Rupert Murdoch is a great guy who likes me much better as a successful candidate than he ever did as a successful businessman," Trump exulted in a Monday tweet liked by 34,700 and retweeted 6,948 times.

In contrast, Trump blasted NBC News in a tweet last Sunday:

Comcast declined to comment on NBC's relationship with Trump or what a new administration might do. But the Philadelphia company noted it has two distinct businesses — entertainment/news, and cable/internet services. And as a business, Comcast does what Trump has said he expects American corporations to do.

"Comcast seeks to work constructively with every new Administration, and we look forward to working with the Trump administration on shared goals such as creating a positive investment climate, investing in American infrastructure, and creating more jobs in the US.," a company spokesperson said last week. "Comcast has invested more than $35 billion in just the past 5 years to bring faster internet speeds and cutting edge video technology to more homes and businesses across the country.  Nearly all of our 153,000 employees are US based and we are a significant cash taxpayer at the federal, state, and local levels."

The potential gravity of the situation isn't lost at NBC, the TV network that helped launch Trump. Greenblatt, chairman of NBC Entertainment, has compared the national exposure afforded to Trump on the  Apprentice shows with the exposure provided to Ronald Reagan in Bedtime for Bonzo, a 1951 comedy film that starred Reagan and reintroduced him to a film-going audience.

"We do talk about it," Greenblatt told Entertainment Weekly. "Bedtime for Bonzo helped Reagan, sort of, become a national prominent figure. Garry Trudeau was predicting that Donald Trump would run for president 15 years ago, before he was on The Apprentice."