Scarborough repeatedly supported Trump's claim that Fox host and debate moderator Megyn Kelly is biased against Trump's presidential campaign.
At one point, Scarborough played a short highlight reel of Kelly's sharper words for Trump and for the media - including Scarborough's "Morning Joe" - regarding some of its relentless Trump coverage.
"That is just good, unbiased journalism," Scarborough said, sarcastically. "And if I were a candidate, I certainly would want that person asking me questions in a fair and a balanced way."
He added: "No, actually, as I said before, I would rather set myself on fire in front of the Fox News news studio than go on the debate stage with that."
Scarborough, a former Republican congressman whose show competes daily against Fox News, further argued that Fox chief Roger Ailes had made a mistake by standing so firmly against Trump.
Trump has repeatedly complained that Kelly would be unfair to him at the Thursday-night event. Fox dismissed Trump's criticism as unfounded and said Kelly would remain one of the three moderators of its debate.
After the network mocked Trump for polling his Twitter followers about whether he should go to the debate, given Kelly's alleged bias, the Republican front-runner announced he would boycott it.
"He's ahead by 20, 30 points. He's probably going to be the front-runner," Scarborough said of Trump at another point in his show. "And when you know that Fox News' viewers tend to trend older and white and male - and Donald Trump's most ardent supporters are older and white and male - is one anchor worth splitting the network's audience right down the middle?"
Scarborough elaborated on that argument later in the day on Twitter:
What's made Ailes a spectacular success and genius is a management approach that put the network above individual stars.
- Joe Scarborough (@JoeNBC) January 27, 2016That's why allowing this destructive fight over one anchor (with an obvious bias against a candidate) doesn't seem out of Ailes' playbook.
- Joe Scarborough (@JoeNBC) January 27, 2016
AP Photo/John Minchillo, File
Donald Trump and Megyn Kelly.
Scarborough also said on his show that Trump's feud with Fox was just the latest in a string of firestorms Trump has ignited in order to manipulate the media. He cited Trump's claim that Mexico was sending "rapists" across the US border and the mogul's proposal to bar Muslims from entering the US.
"It's the press that makes a one-day story a one-week [story] by predicting the bitter end for Donald Trump. And they are always wrong," the MSNBC host said. "And I saw it happening again last night on Twitter: 'Donald's scared.' No he's not! He's scared of losing."
Scarborough added: "And Fox News has just walked into the biggest Donald Trump trap of the 2016 campaign."
For its part, a Fox spokesperson released a lengthy statement noting that Trump had "viciously" attacked Kelly since August, when she was one of the moderators at the first Fox-hosted debate. At the time, Kelly infuriated Trump by asking a pointed question about derogatory remarks he's made about women's looks.
The Fox statement also accused Trump's campaign manager of threatening Kelly:
Capitulating to politicians' ultimatums about a debate moderator violates all journalistic standards, as do threats, including the one leveled by Trump's campaign manager Corey Lewandowski toward Megyn Kelly. In a call on Saturday with a Fox News executive, Lewandowski stated that Megyn had a "rough couple of days after that last debate" and he "would hate to have her go through that again." ... We can't give in to terrorizations toward any of our employees.