Las Vegas has been a prime venue for championship boxing matches which draw a bevy of celebrity types who sit ringside, cheering on their fighters.
On Wednesday, the third and last presidential debate in the Nevada desert city will feature its own assortment of guests to watch close-up as the candidates pummel each other.
Trump has invited Barack Obama’s Kenyan-born half-brother Abon’go Malik, who may harbour some resentment over the president’s refusal to have anything to do with the foundation Malik set up under the name of their father, Barack Hussein Obama senior.
Malik says he believes Trump when the candidate pledges to “make America great again”.
The Republican candidate’s second guest: Patricia Smith, mother of one of the four Americans killed in the 2012 attack on the US consulate and CIA post in Benghazi, Libya.
Both Malik and Smith share a dim view of Hillary Clinton – he calls her a liar and she blames the former secretary of state “personally for the death of my son”.
(Other family members of the Benghazi victims have not joined in the accusations against Clinton.)
Trump’s guests at the second debate were three women who have accused Bill Clinton of sexual offences and another whose grievance stems from the fact that 40 years ago, a judge ordered Hillary, then a legal aid lawyer, to defend a man charged with raping her.
(The debate moderators refused to allow the women to sit in the front row together with Trump’s family.)
It’s hard to tell what calculations Trump made in choosing his latest debate guests.
But it’s curious that Malik has a Libyan connection too.
For three decades he had a close and admiring relationship with slain leader Muammar Gaddafi, a man whose overthrow Trump once demanded, before he switched his position this year and declared: “It would be so much better … if Gaddafi would be in charge now.”
As for Clinton, her two invitees are the kind of self-made billionaires that offer a stark contrast with Trump.
Meg Whitman, a former top executive at eBay and now CEO of Hewlett-Packard, is a staunch Republican.
But this year she’s been campaigning for Clinton after denouncing Trump for “exploiting anger, grievance, xenophobia and racial division”.
Mark Cuban had expressed interest in supporting Trump until he decided that the real estate tycoon was the most “dangerous” presidential candidate imaginable.
Cuban has offered to contribute $10m to charity if Trump agrees to a four-hour debate on his policies.
(Cuban says he’ll give the money to Trump “if he needs it” since Cuban doubts the candidate is nearly as rich as he claims.)
After attending the first debate, Cuban said he’s received death threats from Trump supporters.
The outcome of the debate may not be affected by the sideshow in the audience.
But it’s one more unprecedented oddity in a bizarre election campaign.