Author and conservative firebrand Ann Coulter was not invited to speak at this year's Conservative Political Action Conference, marking the first time in several years that she was not scheduled to attend in an official capacity.

Coulter is usually a popular speaker at the annual conference -- it's the largest gathering of conservatives in the U.S. held this weekend just outside of Washington, D.C. -- where she has delivered well-received speeches and signed her books for fans.

"I wasn't invited," Coulter confirmed in an email Thursday to the Washington Examiner media desk. "I might just show up anyway just to piss them off. I could be the Bibi Netanyahu of CPAC." (The Netanyahu mention is a reference to a controversial invite from congressional Republicans to the Israeli prime minister to address Congress.)

Coulter, apparently confused by the snub from conference organizers, said she has been voted "best speaker" by attendees in previous years.

Lisa De Pasquale, who served as the conference director from 2006 to 2011, confirmed that attendees surveyed after the conference ended consistently chose Coulter as the most popular speaker. "You can definitely quote me on that," said Pasquale.

Dave Hemsath sets up a booth selling books by conservative authors each year at the conference. He told the Examiner that her books tend to sell particularly well among attendees. "She's my best seller," he said. He also said he didn't want to "speak out of turn" but that he's "sorry" he won't be able to sell as many of her books this year, as he didn't bring as many as usual due to her absence from the speaker schedule.

Coulter's strained relationship with conference organizers was also evident at last year's event. She said at the time that she was not invited to speak until two weeks before the conference and that it was sprung on her that instead of a solo speaking slot, she was only offered time used to "debate" a liberal speaker.

Coulter suggested on Twitter that her exclusion might have something to do with immigration reform that includes a pathway to citizenship, a policy front Republicans have struggled with and that Coulter has been intensely critical of. "if I want to watch a bunch of rich white people suck up to Mexicans, I'll watch the Oscars again," Coulter tweeted.

The conference is a big draw for Republican voters and conservatives. Several potential GOP presidential candidates are at this year's event to deliver speeches and answer questions, including Texas Gov. Rick Perry, former Florida Gov. Jeb Bush and retired neurosurgeon Ben Carson.

Other conservative commentators are scheduled to speak at the conference, including Fox News' Sean Hannity and conservative radio host Laura Ingraham, who both spoke on Thursday.

Two separate spokesmen for the conference did not return requests for comment.