Idaho was one of the states I had wrong. After the Washington Caucus, I looked and saw that Romney was not doing that well in the rural areas of Washington, I thought that perhaps another candidate would win in Idaho.
Idaho is a conservative state, but what that means in the Mountain West is not what it means in, say, West Virginia. The culture tends to be a bit more secular, and there are also many Mormons. For these reasons, I thought that Rick Santorum, Ron Paul and Mitt Romney all had a shot at winning Idaho.
Long story short, however, Mitt Romney ended up winning with over 60% of the vote. He had an overwhelming advantage in the heavily Mormon southeast part of the state, and won Boise and its suburbs. While Rick Santorum or Ron Paul carried every county in the Idaho Panhandle, it hardly made a dent in his large margins in the rest of the state. The victory in Idaho cemented Mitt Romney as a strong candidate in the West. It also was another strike against Ron Paul's attempts to win a state on Super Tuesday.