This piece was co-authored by Shawna Shepherd
Columbia, South Carolina (CNN) – With the stroke of a pen this weekend, Arizona Gov. Jan Brewer could single-handedly blow up the carefully laid-out Republican presidential primary calendar.
Saturday is the deadline for Brewer to decide whether to move Arizona's 2012 primary up to January 31 in an effort to give her state greater influence in the GOP presidential race. The primary is currently slated for Feb. 28. But Brewer's move would not only violate Republican National Committee rules that forbid any state other than Iowa, New Hampshire, Nevada and South Carolina from holding a primary or caucus before March 6, it would also compel those first four states to move up their own contests to protect their cherished early state status.