Iowa used to be a strong GOP state but it’s gone through some weird bouts since the Watergate years. For one thing, it seemed to have a dovish streak that doesn’t sit well with the national Republican Party. In 1984, it only gave Reagan a 53%-46% win over Mondale, than in 1988 it gives Dukakis a huge percentage, bigger than Massachusetts (!) It sometimes swings back to the GOP, but never to the point that it turns into another Kansas or Nebraska. It seems now to be divided mostly between a heavily Republican west and a more Democratic east. The bigger counties east vote Dem, but even quite a few of the smaller counties there also vote Dem. Maybe it’s a more populist area? I don’t know.
It does seems like a truly peculiar mix of Minnesota & Kansas. The MS River counties are especially queer. Some, like Dubuque County, have not voted Republican for President in the modern era (1960-onwards). McGovern won 50-47% in 1972, in 1980 Reagan lost the county by FORTY votes to Carter (with John Anderson getting 9%), Mondale took it 53-46% in 1984, and Dukakis in '88 by a jaw-dropping 62-38% (placing it a whopping 16% to the left of the entire country - moonbat by any estimation).
The highest % a Republican has gotten in Dubuque County since was Dubya's 43% in 2004 when he carried the state. Willard did get 42%.
Oddly, Dubuque has voted GOP for Governor and Senator (in 1994 it went with Branstad where he got 53%, though in 2010 it went with incumbent Gov. Culver, 50-48%). In 2010, Sen. Grassley carried the county 59-39%.
Here's the 2012 Pres. results with the proper Red/Dem, Blue/GOP colors. Curiously, that one "Red" Dem county in the western part of the state, Woodbury (which contains the Omaha suburb of Council Bluffs) was the only county that swung the opposite way to the rest of the state, voting for McCain in 2008 (49.6-49%) but for Zero in 2012 (49.5-48.5%). Odd, if only because Omaha's Douglas County, NE across the river went for Zero in 2008 but swung back to Willard in 2012.