Libertarian Party debate in Las Vegas last month featured Penn Jillette — you know, the talking half of Penn & Teller — as the moderator. Other questioners included Carrot Top, Drew Carey, Clay Aiken and Arsenio Hall.

The discourse was more substantive than one might have expected — no thanks to Carrot Top, who just wanted to know what slogans the candidates might put on Donald Trump-style trucker hats — but for a party that wants to be taken seriously in presidential politics, the entertainer-laden event probably didn't advance the cause.

This is why Wednesday's Libertarian town hall — live in prime time on CNN — is a big deal. It marks the first time Libertarian candidates will participate in a live presidential forum on one of the three major cable news channels. Chris Cuomo, who has moderated town hall events with Hillary Clinton and Bernie Sanders this election, will run the show, posing questions to Libertarian nominee Gary Johnson and his running mate, Bill Weld, while also fielding inquiries from the audience.

Notably, CNN is billing the questions as being "similar to those posed to the Democratic and Republican candidates during the primaries." In other words, CNN is taking Johnson and Weld seriously — for an evening, at least.

The two former governors (Johnson of New Mexico and Weld of Massachusetts) have enjoyed a spike in coverage lately. With the presumptive major-party nominees registering historically bad favorability ratings, the Libertarian ticket — which Johnson also led in 2012 — is getting more attention than usual. In polls that include him, Johnson's support averages 8.5 percent, according to RealClearPolitics.

But much of the coverage has centered not on what Johnson stands for but what effect he might have on Trump and Clinton. Which of the two real contenders is more likely to lose voters to this third-party interloper? Could he somehow prevent either one from winning a majority in the Electoral College by picking off a state or more (Utah anybody)?

Those are worthwhile considerations, but CNN's town hall figures to give the Libertarian nominee an opportunity on a big stage to talk about more than playing spoiler.

"It's sort of a perfect setup for Johnson and Weld to go more in-depth," said Mitchell McKinney, who chairs the communication department at the University of Missouri. "What else do they believe? This will give them a chance to flesh that out."

McKinney has studied presidential debates that include third-party candidates — a small sample that includes, most recently, three from 1992, when independent Ross Perot joined Republican President George H.W. Bush and Democratic nominee Bill Clinton. McKinney found that outsiders like Perot are often ignored for long stretches and, when questioned, asked not about their policies but about their credibility as candidates.

A town hall format, with no opponents on the stage, should mitigate the dismissiveness, McKinney said. He added that a good showing by Johnson could help him qualify for general election debates in the fall. Johnson would have to get his poll numbers up to 15 percent.

Larry Diamond, faculty director of the Haas Center for Public Service at Stanford University, is a leading advocate for lowering the threshold to 10 percent. He believes the Commission on Presidential Debates, which sets the rules, is "clearly biased against the entry of a third option." (Commission co-chair Michael McCurry told the "Open Mind" public television program in January that a third candidate "would be welcome in these debates.") Whatever the case, Diamond thinks CNN's decision to host a Libertarian town hall is a "modest but noteworthy development."

"Maybe more significant is that the Libertarian ticket is starting to get more media attention generally," he said.

A CNN spokeswoman did not respond to questions about why the cable channel decided to sponsor the event.

The closest Libertarian candidates have come to the level of exposure they stand to receive Wednesday was a primary debate that aired on tape delay — in two parts, a week a part — on Fox Business Network in April. Libertarian journalist John Stossel moderated.

"It was John Stossel who first raised the issue about the lack of national media attention the Libertarian Party was receiving," said Bill Shine, senior executive vice president of programming at Fox Business. "And with the growing number of disenfranchised voters, we thought it was important to help viewers vet the candidates before the party tickets were declared. We're flattered that CNN decided to follow our lead months after the fact."

The question for Johnson and Weld is whether others in the media will follow suit. The CNN town hall could signal a new, more legitimate status for the Libertarian candidates in the eyes of the press. Or it could be a novelty event created to fill a slow Wednesday evening between the end of the primaries and the start of the major-party conventions. We'll see.