On Monday night, CNN, the New Hampshire Union Leader and other sponsors will hold a debate in New Hampshire -- and Mitt Romney, Newt Gingrich, Ron Paul, Herman Cain, Tim Pawlenty, Michele Bachmann and Rick Santorum will all be attending.

That's virtually every major declared Republican candidate. Except one. And that exclusion -- and the reasoning behind it -- is downright puzzling.

Meet Gary Johnson. He's a two-term governor of New Mexico. (That's one more term than Mitt Romeny and almost two terms more than Sarah Palin.) Johnson holds many positions that Republicans might like: While governor, he did what most politicians find impossible: Actually shrinking government (not just slowing the expansion of government). He vetoed more bills than the 49 other governors combined.

But it's not just the fact that Johnson has more top executive experience than any other GOP candidate (or his success in the very-difficult art of actually limiting government) that makes his exclusion strange. He also qualifies for inclusion in the debate based on CNN's own criteria.

CNN's criterion No. 2 states that any candidate who demonstrates the following will be included in the debate: "A candidate must have received an average of at least 2.00 % in at least three national polls released between May 1 and May 31 that were conducted by the following: ABC, AP, Bloomberg, CBS, CNN, FOX, Gallup, Los Angeles Times, Marist, McClatchy, NBC, Newsweek, Pew, Quinnipiac, Reuters, USA Today and Time."

The Johnson campaign quickly jumped on this criterion and produced required three polls (by CNN, Gallup and Quinnipiac) whose average puts Johnson squarely at 2 percent.

The debate organizers responded: Those polls aren't good enough. Those polls were "restrictive" polls and we only count "unrestrictive" polls, they now say.

“The debate is open to unannounced potential candidates who have significant public support," said Charlie Perkins of North Village Media, a debate organizer and former news executive at the New Hampshire Union Leader. "Therefore, invitations could not be based on restrictive polling that excluded those names."

The problem, however, is that stated criteria do not prohibit the inclusion of "restrictive" polls, as Perkins states. (You can view the criteria here.) Nowhere do the rules state that only "unrestrictive polls" can be counted. Therefore, this last-minute alteration of the criteria is akin to that most-hated sports analogy: Changing the rules in the middle of the game.

It's not fair in sports and it's not fair in politics. Johnson should be included in the debate. The debate organizers, if they wish, should specify their demands of unrestrictive polls for future debates prior to publishing the criteria. They didn't in this case. And they shouldn't change the rules to justify the exclusion of a candidate whom they had already improperly decided to exclude.