Kerry's strength in the state lay in the highly populated counties of
Polk (
Des Moines),
Linn (
Cedar Rapids),
Scott (
Davenport),
Johnson (
Iowa City), and
Black Hawk (
Waterloo). Johnson County, home to the University of Iowa, gave Kerry 64.01% of its vote, Kerry's best performance in the state. However, Kerry also did well in a series of rural and small-town counties in northeastern Iowa and along the Mississippi River, many of which had been traditionally Democratic since at least the 1980s. He won eight of the ten counties along the Mississippi River, including
Dubuque County, which had given Gore his margin in the state in 2000. The
1st and
2nd congressional districts were both carried by Kerry, despite being represented by
Republicans in
Congress.
Dubuque is located within the 1st district while the 2nd district contains Cedar Rapids, Iowa City, and
Muscatine. However, Bush performed respectably even in areas of Democratic strength; in only two counties did he obtain less than 40% of the vote. Additionally, he was able to offset Kerry's strength in the population centers and in the northeast and Mississippi River counties with landslide margins in a series of rural counties in the west of the state, as well as by dominating the state's south. Bush's best performance in the state was in
Sioux County, where he won with 85.87% of the vote. His raw vote margin in Sioux County of 11,970 votes alone was greater than his raw vote margin over Kerry statewide. Bush won three congressional districts in the state: the
3rd district, home to the Democratic city of Des Moines and its Republican suburbs, gave Bush a razor thin 50–50 margin, despite re-electing Democrat
Leonard Boswell to Congress. The
4th district also gave Bush a narrow margin, giving him 51% of the vote. The now obsolete
5th district in the western part of the state was home to Iowa's most Republican areas, having elected
Steve King to Congress in
2002; it gave Bush a landslide 21-point margin. In terms of counties carried, both candidates flipped counties. Bush flipped four that voted for Gore in 2000, while Kerry flipped five that voted for Bush in 2000. This election coincided with the
2004 United States Senate election in Iowa, where
Republican Chuck Grassley was effortlessly re-elected with 70.83% of the vote. Iowa would return to the Democratic column in the next two elections, voting for
Barack Obama by 9.54% in
2008 and 5.81% in
2012. However, it would return to the Republican column since then when
Donald Trump won the state by 9.41% in
2016 and 8.30% in
2020. In
2024, Trump won the state by 13.21%, the largest margin of victory for a Republican presidential nominee in the state since
Ronald Reagan's in
1980. ==Results==