Arizona's huge LDS population gives Mitt Romney a built-in advantage in that state, and that's why he will likely win there on Tuesday.
Nate Silver at FiveThirtyEight.com says Mormon voters make up 11% of the electorate in Nevada, which is a huge advantage for him.
The most tangible advantage in Arizona belongs to Mitt Romney, and it is because the state has a reasonably high Mormon population. In the 2008 primary there, Mormon voters constituted 11 percent of the electorate — and Mr. Romney won 88 percent of their votes, versus 8 percent for John McCain.
If Mr. Romney posts similar numbers among Mormon voters this year in Tuesday’s primary — and there’s no reason to think that he won’t — that works out a nine-point built-in advantage in the state.
Without that Mormon edge, in fact, the state would essentially be a toss-up. Mr. Romney is now projected to win the state by 11 points over all, according to a FiveThirtyEight forecast model, which works out to an 89 percent chance of winning given the uncertainty inherent in the forecast.