Lots of speculation today about the fact that on Thursday there is a “To Be Announced” hole in the list of speakers, right before Mark Rubio and Mitt Romney.

Some speculate it could be Sarah Palin but that seems unlikely given her polarizing nature with swing voters.

Over at Daily Caller they are speculating it could be Joe Lieberman or Colin Powell among others.

Other speculation covers pretty much anyone you can think of.

So what do you think ?