The Republican National Convention is abuzz with speculation over the identity of a mystery speaker who’s supposed to appear Thursday night.

Convention officials have refused to reveal who will fill the “To Be Announced” slot on the closing-night schedule, but the list of possibilities being generated by convention delegates and observers stretches from Hollywood (Clint Eastwood) to hologram (Ronald Reagan) to a handful of conservative favorites who fall somewhere in between.

Republican National Committee Chairman Reince Priebus refused to give even the smallest hint Wednesday.

“Everyone’s going to have to tune in on Thursday night and check it out,” he told Fox News.

Rumors were flying on the convention floor Wednesday afternoon that Hollywood icon Eastwood is the surprise guest, the speculation fueled by reports of the actor and director’s travel plans.

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