Big 12 expansion: Arizona Wildcats could leave Pac-12, Arizona State Sun Devils could stay

The speculation surrounding the Arizona Wildcats and Arizona State Sun Devils potentially joining the Big 12 Conference has led to a very interesting question.
Could just Arizona leave for the Big 12, leaving Arizona State in the Pac-12?
In the past, the answer to that question would have likely been a resounding no, but there are some indications that the Wildcats and Sun Devils could no longer be a package deal in conference expansion and realignment.
Arizona seems to be more interested in joining the Big 12, while Arizona State has seemed to be more interested in the status quo, staying in the Pac-12.
247 Sports' Brandon Marcello wrote: "(Big 12 Commissioner Brett) Yormark's primary target is Arizona, sources tell 247Sports. The university is open to discussing its future and the Big 12 has communicated with the Wildcats' leadership for several months. Members of Arizona's board of regents have expressed a desire to keep Arizona State and Arizona in the same conference, sources tell 247Sports, but that is not expected to be a roadblock if the Wildcats want to go alone and join Colorado in the Big 12. Arizona State's university leadership has been cautious with the changing landscape and is not bullish on moving to the Big 12, sources tell 247Sports."
Arizona president Robert C. Robbins left the door open for Arizona and Arizona State to be in different conferences with some comments last month.
“We don’t have to do the same thing,” Robbins told ESPN's Pete Thamel about the possibility of the two Arizona schools ending up in different conferences. “But [ASU] President [Michael] Crow and I are very, very tight. I think it’d be unlikely that we’d be split up. Right now with 10 schools, we control a very nice 20% of solidarity.”
Robbins on the ties between Arizona and ASU in a realignment scenario: "We don’t have to do the same thing. But President Crow and I are very, very tight. I think it’d be unlikely that we’d be split up. Right now with 10 schools, we control a very nice 20-percent of solidarity."
Interestingly, in comments last month, Robbins predicted that all 10 schools would stay in the Pac-12, which obviously hasn't happened with Colorado leaving for the Big 12.
“Each of us will make our own independent analysis,” Robbins said of the Pac-12 schools, via The Associated Press. "My prediction is that we’re all going to stay together as a Pac-12. There’s 10 of us right now. I’m hopeful that the deal is going to be good enough to keep us together.”
Recent odds seem to like Arizona and Arizona State's chances to join the Big 12 together.
Sportsline.com put the Wildcats at +300 to be the next team in the Big 12. Arizona State was at +400. The closest school to the Arizona schools was Utah at +600.
There is still a belief that Arizona and Arizona State would both join the Big 12, together, even though they might not.
Sportline's Matt Severance wrote: "Arizona has been the more engaged and more closely targeted school than Utah and Arizona State. Arizona president Bobby Robbins has said no decisions will be made until there's clarity on the Pac-12's television deal, but Colorado bolting could change the dynamic. If Arizona leaves for the Big 12, ASU almost surely will eventually do so as well."
Mac Engal of the Fort Worth Star-Telegram wrote: "According to sources, the Big 12 and Yormark is now targeting the University of Arizona, which would likely mean an invitation to Arizona State University."
Not matter what happens with conference realignment for the Pac-12 and Arizona. One thing is certain, both the Wildcats and ASU will be in the same conference.