Southwest Airlines took over the St. Louis market a few years ago and the same thing could happen in Phoenix, thanks to the merger between US Airways and American Airlines, said Tom Parsons with BestFares.com
The new American Airlines will downsize flights in and out of Sky Harbor and that leaves Southwest with a golden opportunity.
"There's always been a dogfight between America West/US Airways and Southwest," said Parsons. "Southwest will look very seriously at making Sky Harbor a very good connecting point and keeping the number of flights up."
Parsons said both American and Southwest should be concerned with an up-and-coming airline at Gateway: Spirit Airlines is making huge strides in Dallas and Houston right now.