HEMPSTEAD, N.Y. — It makes sense that Donald Trump’s iconoclastic presidential campaign would feature the most unique set of surrogates in political history: legendary college basketball coach Bob Knight, boxing promoter Don King and unconventional university President Jerry Falwell Jr., each of whom was wandering the press hall ahead of Monday’s presidential debate.
“I just think that is a testament to the fact that he is the people’s candidate,” said Mr. Falwell, president of Liberty University. “It is something we just haven’t had. We’ve had an establishment candidate one after another in both parties for so long, and I think people are finally seeing through it. They finally got sick of it.”
In a campaign that has been just as much a reality TV show as a policy conversation with voters, Mr. Trump has repeatedly tested years of political conventional wisdom. He has questioned fellow candidates’ manhood, engaged in a virtual shouting match with the pope and insulted entire nationalities.
He also has shaken the political map, upending two decades of states firmly inked red, blue and purple by putting new states in play — for both parties.
Mr. Falwell, who made a huge stir early this year when he endorsed Mr. Trump, even as many other evangelical Christian leaders were ruling out the billionaire businessman, said he wasn’t surprised to be joining a crew with Mr. King.
“The only people in my town who were supporting Trump before I was were African-American friends of mine. It is amazing how diverse his supporters are — from all walks of life and from all races and religions,” Mr. Falwell said after he moseyed over to get a glimpse of Mr. King.
Mr. Trump’s Democratic opponent, Hillary Clinton, has run a classic establishment-style campaign, raising and spending hundreds of millions of dollars, building a massive machine and attacking her opponent on television.
Her public statements are usually devoid of news unless she intends it — though she has stumbled in a candid moment, saying she deems half of Mr. Trump’s supporters “racists” and “haters,” which she dubbed a “basket of deplorables.”
Her nominating convention in Philadelphia featured a who’s who of Washington politicians, while many Republicans in Congress avoided Mr. Trump and the national convention.
Instead, it was the likes of Mr. Falwell, who spoke in person, and Mr. Knight, who spoke by video, in Cleveland.
“It is unique cast of characters for a unique candidate. I think it just adds to the sideshow that defines his campaign,” said Mo Elleithee, a spokesman for Mrs. Clinton in 2008, who now runs the Institute of Politics at Georgetown University.
“Let me put it this way: If his goal here is to show that he’s got enough substantive background, enough substantive knowledge to pass the commander-in-chief test, I just don’t think Don King is the guy to help sell that argument,” Mr. Elleithee said.
But Mr. King’s presence was, perhaps, perfect for the Twitter age of the campaign. Photos of him in the press center quickly made their way across cyberspace Monday night.
“He has the will of the people in support of him, and I think every black kid [should] vote for him because this is the first opportunity in the history of the country that the blacks have the opportunity to vote on an issue that has never been on the ticket before — their system, which is the creator of all the problem — the rigged, corrupt, racists, sexist system that we have been able to be governed by,” said Mr. King, who was wearing slip-on shoes with an American flag design.
Mrs. Clinton didn’t entirely avoid the celebrity surrogate game, inviting Mark Cuban, a billionaire businessman who has competed with Mr. Trump in reality television and is a fierce critic of the Republican nominee.
When he learned that Mr. Cuban would be a guest of Mrs. Clinton at the debate, Mr. Trump tweeted that he might counter by inviting Gennifer Flowers, with whom Mrs. Clinton’s husband, former President Bill Clinton, has admitted he had an affair.
The Trump campaign later squelched those plans.
Mr. Trump, a prolific tweeter, said he was relinquishing control of his powerful Twitter account for the duration of the debate Monday.
“My team of deplorables will be managing my Twitter account for this evening’s debate,” he said in a post to his nearly 12 million followers.
Mrs. Clinton’s own account has nearly 9 million followers, though she is personally far less active and her account is run by her campaign team. Posts that are directly from her are signed with “-H.”
Hours ahead of the debate, Green Party nominee Jill Stein, who was banned from the debate for low poll numbers, staged an “occupy” protest outside the gates of Hofstra University, complaining about her treatment by the commission that runs the debates.
“What do we want? Open debates! When do we want it? Now!” chanted a crowd at the demonstration, which was streamed live on Twitter’s Periscope app.
Police earlier escorted Ms. Stein out of the debate hall when she couldn’t show proper credentials, ABC News reported.
• Stephen Dinan in Hempstead, New York, and S.A. Miller in Washington contributed to this report.