What makes you think is not a liberal democrat?
He may be, in which case the RINO Super PAC's that backed him have wasted their money. The way I look at it any time an entrenched 8-term Democrat like Tierney gets turfed, it opens up opportunities for the GOP. We could try to primary this guy in 2014 if he turns out to be the liberal he's accused of being. Even if he switches parties mid-stream, the district has lost Tierney's 8-term seniority in Congress, which is an important reason why voters continue pulling the lever for incumbents.