Walker has advantages in Iowa. He’s from a next-door state and has the backing of Iowa Gov. Branstad. That Branstad machine would likely switch to Christie if Walker’s out.
Christie is Chairman of the Republican Governor’s Association and appears with Branstad in Iowa whenever possible.
Rubio gets high on the list because Iowa talk radio shows give him ample interview time.
Iowa is strictly a beauty pageant with no prizes except publicity.
I like Walker. His victories in WI indicate he has the potential to win the Rust Belt states in the general. Given the GOP lock on the red states, that's all he needs to do to get to the White House. Assuming he gets the nomination.