http://www.slate.com/articles/news_and_politics/map_of_the_week/2012/08/map_utah_wyoming_idaho_are_the_most_republican_states_.html
And then quoting from your new favorite poll ...
Utah wins out over BYU when it comes to college sports loyalties in the state, 32/26. Utah State is third at 16%, followed by Weber State at 4%, Southern Utah at 3%, and Utah Valley at 2%. There are massive political and religious divides on college loyalty. Among Democrats Utah leads with 54% to 15% for Utah State, with BYU only tied for third with Utah Valley at 5%. But among Republicans BYU wins out with 40% to 21% for Utah, and 15% for Utah State. The political divide mirrors the religious split- among Mormons, BYU leads with 40% to 20% for Utah and 17% for Utah State. But among non-Mormons Utah romps with 55% to 14% for Utah State with BYU registering at only 1%.
http://www.publicpolicypolling.com/pdf/2015/PPP_Release_UT_82416.pdf
So, yeah, it's sort of a big deal to get the state's political leanings off by double digits when making conclusions about team loyalties.
I think Utah has made strides over the past decade for sure to secure a more solid fanbase within the state (esp SLC), but lets not pretend that they "own" the state. At this point, I would say it's pretty even for BYU/Utah ... but then you have to account for the fact that over 60% of BYU's fanbase resides OUTSIDE of utah. For the Utes that number is single digits.