The Americans for Prosperity Foundation, a tea party-affiliated group funded by the Koch brothers, will hold a summit in New Hampshire next month. Among attendees will be some familiar names with buzz about trying for the Republican nomination for the 2012 nomination.

Tim Pawlenty will be in attendance, as will Rick Santorum.

Haley Barbour, Sarah Palin, Mike Huckabee and Newt Gingrich have all been invited, but it is not confirmed whether they will be attending.

Not attending, and not invited: Head of the Congressional tea party caucus, Rep. Michele Bachmann.

"We're not trying to exclude Michele Bachmann by any stretch of the imagination," AFPF New Hampshire State Director Corey Lewandowski told National Journal. "What we did is we looked at the criteria of individuals back in December [when the invitations were sent] who had at least some media coverage as a potential candidate. It's fair to say that at that point, Michele Bachmann … hadn't had any serious press about that."

However, low-profile businessman Herman Caine was invited and will attend, while South Dakota Sen. John Thune, who has announced that he will not seek the presidency, was invited and declined.

AFPF has said that they will limit five candidates at the event, though they do not make endorsements.