Iowans will elect 25 state senators today. Those races have attracted far less attention than this year’s Iowa House races, because Republicans have a lopsided 32-18 majority in the upper chamber and only a 53-47 advantage in the House.

Nevertheless, it’s important to keep an eye on the Senate races, because this year’s outcome will influence Democratic prospects under the new map coming in 2021.

This overview covers five districts where both parties are spending six-figure amounts, seven districts where Republicans spent a significant amount, and four more districts where the results could shed light on political trends in various parts of the state, even though neither Democrats nor Republicans targeted the race.