Donald Trump left a big impression on the Conservative Political Action Conference last year without even showing up.

He was cruising to the Republican presidential nomination at the time, but backed out of the annual confab the day before he was scheduled to speak amid rumors of a planned revolt over his appearance.

Trump is back on the schedule at this year's CPAC, which kicks off Wednesday afternoon outside Washington. And while the conference will have a decidedly Trumpian feel, the fissures on the right that were exposed by his campaign are still very much in place.

The lineup is highlighted by Trump's allies both in the White House and the media -- and, of course, the president himself, who is scheduled to address the conference on Friday.

Steve Bannon, the former chairman of Breitbart News who now serves as one of Trump's top advisers, will appear on a panel Thursday with White House chief of staff Reince Priebus and Matt Schlapp, the chairman of the American Conservative Union, which sponsors CPAC.

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Several other staffers from Breitbart, whose adoring headlines and fawning coverage of Trump have prompted some to call it a de facto propaganda arm of the White House, are also on tap to speak. So are Sean Hannity and Lou Dobbs, hosts at Fox News and Fox Business respectively, who have been among Trump's biggest media boosters.

But much like a year ago, CPAC may be most remembered for who isn't there.

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Milo Yiannopoulos, the right-wing commentator, had his invitation rescinded after the release of video clips in which he appeared to speak sympathetically about sex between "younger boys and older men."

The controversy also cost him a book deal with Simon & Schuster and his job as tech editor at Breitbart.

Yiannopoulos maintains the clips were deceptively edited. But even before they were released, the decision to include him at CPAC had set off an uproar among prominent conservative commentators.

Schlapp faced intense criticism on Twitter, perhaps most notably from National Review senior editor Jonah Goldberg.

In an email to CNNMoney earlier this week, Goldberg said that Yiannopoulos' association with the alt-right, a movement animated by white nationalism and anti-Semitism, "should be the only red flag CPAC needs."

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The controversy over Yiannopoulos served as a reminder that many establishment conservatives still refuse to accept the alt-right, despite the makeup of the current administration. (Bannon once called Breitbart "the platform for the alt-right.")

Ned Ryun, a board member for the American Conservative Union, vehemently objected to Yiannopoulos' invitation to CPAC.

"We disinvited him over pedophilia," Ryun told Politico. "The debate I wanted to have, and which Schlapp didn't want to have, is why are we inviting somebody who calls himself a fellow traveler of the alt-right?"

Goldberg speculated that CPAC "is a creature of Donald Trump, Breitbart, Bannon," as well as Robert Mercer, the hedge-fund billionaire who has been a benefactor to Breitbart.

"Another possible motive is that it's good box office in the same way the Ann Coulter show is," Goldberg said. "I think that's terribly misguided and represents very bad stewardship of the conservative brand. But it's the kind of mistake you'd expect when Conservatism Inc. becomes more important than conservatism."

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Trump was ridiculed by conservatives and his GOP rivals when he pulled out of CPAC last year, following reports that activists were planning a walkout during his speech.

"I think someone told him Megyn Kelly was going to be here," Senator Ted Cruz joked at the conference, referring to the former Fox News host who drew Trump's ire on the campaign trail.

Schlapp called Trump's decision to pull out a "whiff," "a mistake," and a "missed opportunity." And CPAC's official Twitter account said Trump's decision "sends a clear message to conservatives."

But despite the residual divisions from the GOP primary, Trump enjoys widespread support among his party's voters. The most recent CNN/ORC poll showed his approval rating at 90% among Republicans.

Schlapp said that he expects Trump to receive a warm reception at CPAC this year. During an appearance Wednesday morning on CNN, Schlapp said it was a "great honor" to have the president at the conference.

"I think he's making quite a statement -- a statement of respect -- to the conservative movement, which is the heart and soul of the Republican movement," he said.