Jeb Bush hasn’t even appeared yet on the debut of “The Late Show With Stephen Colbert,” but this week he already has taken some skewering from the host, after the former Florida governor’s campaign launched a fund-raising contest to win a ticket to the show.

“No one from Jeb’s campaign asked me if this was OK with me to raise money off my first show,” Colbert said, in a YouTube video post this week laced with irritation and humor.

But there’s good reason for Bush to grin and bear it: attention.

As an expanded field tries to stand out, and as Donald Trump takes so much airtime, late night TV may be more important than in past cycles as a way to draw an audience.

Bush is doing the show even though it’s unclear just what tone the show will take, or even what Colbert, no longer playing the satirical conservative host, will be like.

“Bush needs to take a risk; he has been slipping in the polls,” Dave Berg, who, as producer on “The Tonight Show With Jay Leno,” was tasked with securing political guests, told Variety’s “PopPolitics” on SiriusXM on Thursday. “Trump and [Ben] Carson now are leading in Iowa, with Carly Fiorina coming in second. So Bush needs to do something to stand out.”

Bush’s June 16 appearance on “The Tonight Show Starring Jimmy Fallon,” in which he did a somewhat suggestive “slow-jamming” of the the news, did not produce a spike in the ratings. But it’s expected that Colbert’s debut will not only draw strong ratings but also media attention, with segments replayed on Wednesday’s morning news shows and sent out on social media.

On Monday night, Chris Christie appeared on “The Tonight Show Starring Jimmy Fallon,”  drawing some headlines when Christie said that he would “go nuclear” if he is not called upon more frequently at the next GOP presidential debate on Sept. 16. Christie also jokingly walked off the set when Fallon made a quip about the New Jersey governor’s weight.

That show actually posted lower overnight ratings than it did the rest of the week, but that may not make any difference to Christie’s campaign. According to Zignal Labs, an analytics firm that studies impressions across social and traditional media, Christie got a 17% spike in social-media mentions and a 12% spike in TV mentions.

“That’s a sizable bump for a candidate who has struggled to break through the massive GOP field,” said Josh Ginsberg, CEO and co-founder of Zignal Labs.

Ginsberg offers perspective on the challenge that Christie faces: On seven separate days in August, Trump was mentioned more often than Christie was in the entire month.

That ability to get some attention surely played into Rick Santorum’s decision to appear on the Aug. 25 edition of “Real Time With Bill Maher,” in which he sparred with Maher on issues like climate change.

Santorum, polling at or near 1% nationally, according to Real Clear Politics, doesn’t have much to lose by going on a show whose host is diametrically opposed on just about every major issue.

His spokesman, Matt Benyon, said they were pleased with the appearance. “Senator Santorum is always open to appearing in any venue that provides him with an opportunity for a civil debate, whether that be on a show hosted by a liberal or conservative,” he said via email.  “You cannot win a debate if you never make your case, and that is what the senator tries to do wherever he appears.”

When Bill Clinton played saxophone on “The Arsenio Hall Show” in 1992, it was considered novel for a presidential candidate to take to late night. Now it is expected that candidates will appear at least once or even multiple times.

Later next week, Colbert’s guest on Sept. 10 will be Vice President Joseph Biden, who is pondering getting into the race for the Democratic nomination. The following night, Trump will guest on “The Tonight Show.” Bernie Sanders is scheduled for “The Late Show” on Sept. 18. Hillary Clinton also is expected to make the late-night rounds, as she did in her 2008 campaign, but no appearances  have so far been announced. She will appear on “The Ellen Show” on Sept. 10 and 11.

Campaigns see such appearances as ways to boost a candidate’s likability to an audience who may not be glued to politics, but recent cycles have seen shows take on added significance.

After his famous “oops” moment during a presidential debate in 2011, Rick Perry went on “Late Show With David Letterman” to read the top 10 list in an effort at damage control, trying to diffuse the embarrassment with humor.

As the economy spun downward during the fall campaign of 2008, Republican nominee John McCain suspended his campaign and canceled a planned appearance on “Late Show with David Letterman,” drawing mockery from the host as he showed that the candidate instead chose to do an interview with Katie Couric, then anchor of “CBS Evening News.” McCain’s senior adviser Steve Schmidt later called the decision to cancel on Letterman a mistake. “The notion that voters filter the content depending on the type of show it is on is wrong,” he said.

Bush’s appearance on Colbert could end up being mutually beneficial.

“He is a little bit on trial with conservatives,” Berg says. “He has just sort of bashed them through his character for nine years. I think that he has gone out of his way recently to say, ‘I am a regular guy. I am a neutral American. I taught Sunday school.”

Robert Lichter, director of the Center for Media and Public Affairs at George Mason University, said that Colbert needs to expand his audience beyond that of “The Colbert Report,” which on average drew less than a third of the audience of Fallon’s “Tonight Show.”

“I am sure no matter what he does, Republicans will claim he is one-sided and biased,” Lichter says. “But he needs to have a show that isn’t a show for liberals the way that the Comedy Central show was.”

Colbert’s writers were busy preparing for the debut and unavailable for comment. But at this year’s Television Critics Assn. session in Los Angeles, Colbert told reporters, “On the old show I wore the character as lightly as a cap. I could dial it up and down as need be. I’m looking forward to being sincerely interested in what they have to say without having to translate it through an idiot’s mouth.”
That said, Bush would be well advised to have an answer at the ready if Colbert asks how his show became not just a campaign stop but a way to raise a few extra fundraising bucks.