Is Mike McCarthy possibly the Saints next head coach if Dallas lets him walk?

Jones likely isn't going to let McCarthy walk. He's not very reactive and that Dallas team, while it hasn't played well, has continued to fight w/ Jones publically complementing him for not allowing them to give in. If his handling of Jason Garrett is any glimpse into what he's likely to do, McCarthy is getting resigned.

Would he be a candidate? Absolutely...the familiarit for Loomis is there and he fits the "experienced" criteria that Loomis values.
Jones doesn’t get a say in it other than the offer he makes Mike, which, that is a big part of it. However, if Mike wants to leave there’s nothing that can be done.

Hopefully he stays put.