I wonder how much influence Ryan had in all of this. In his homeland, I suspect he is rather intensely admired among Pubs, and Mittens just romped in WI-01 - and perhaps beyond his borders to the Milwaukee metro area as a whole. Absent that, the numbers for WI as a whole might have been really tight. This is one case where an endorsement from someone who has a lot of real substance upstairs, may have been a substantial influence. I wonder how much the media will pick up on this aspect.
WI-1 and WI-5 were districts McCain also romped in, while granted you can't always lump McCain's areas and Mitt's into one they do share some similarities. With or without Ryan, Santorum was always going to do better in the more rural areas of the state and Mitt was going to do better in the suburban areas.