Sarah Palin is the latest in a string of prominent conservatives who have decided not to attend this year’s Conservative Political Action Conference, which takes place in Washington D.C. next week. While this will be the third year in a row that Palin has skipped the event, this year she turned down the coveted keynote-speaker slot, which was filled by Glenn Beck last year and by Rush Limbaugh in 2009:

CPAC leaders invited Palin to deliver the closing-night keynote speech on Saturday Feb. 12, immediately following the announcement of the results of CPAC’s annual presidential straw poll, but after several days of negotiations, she declined.

“We’re disappointed that she wasn’t able to make it this year,” American Conservative Union Chairman David Keene said through a spokesman on Thursday. He noted that Palin “expressed interest in wanting to come this year,” but said that it came down to “a scheduling issue.”

As ABC News noted, Palin “has a rocky history” with CPAC and skipped the event last year owing to some of the reportedly shady business dealings of the conference’s organizer, David Keene. But the fact that she hasn’t attended the event for three years in a row makes it seem like it could honestly be about scheduling issues, as opposed to any involvement in the social conservatives’ CPAC boycott.

Marco Rubio will also be absent, and it will be interesting to see if any other prominent politicians skip out. The Senate will be out of session next week — since Democrats will be away on a retreat — and it’s possible that some GOP senators slated to speak at CPAC will decide to head to their home states at the last minute. But at the moment, the conference apparently hasn’t been seriously impacted by the boycott, and organizers told ABC News that they expect around 10,000 attendees at the event.