How does quitting, giving up a seat to the GOP, and sitting on the sidelines for four years help Matheson? I actually live in this district - Mia seems like a fine candidate. Mike Lee is an excellent speaker and is earning kudos for standing up to Oamacare - he will be ok in 2016.
He did not quit, he will be in office until the expiration of his term in 2015. So he will be in good shape to run for Lee's seat in 2016.
Notice Lee's approval numbers? especially among the GOP in the state as a whole, they stink. The Utah establishment wants Lee out and if Leavitt or some big name establishment candidate cant take Lee out in the primary they will support Matheson in big enough numbers for him to win IMO. The Matheson name is political gold in Utah as you undoubtedly know. He's probably the only Dim that can win a statewide race there.
Mia is not a Conservative, one of Hatch’s to adviser's recently joined her campaign. If you like Hatch you will like Mia but she is not a conservative. I'm not saying this is bad news if you are an establishment Utah Republican but if you are a conservative it increases the chance that Lee will lose exponentially