AP
The Iowa race was one of the most important ones in the country for Democrats, who had once expected to hold the seat of outgoing Sen. Tom Harkin (D) in a state twice won by President Barack Obama.
This made the state one of two pickups in tossup states with Democratic senators Republicans needed to get the net gain of six Senate seats that would allow them to take over the U.S. Senate. In addition to these gains, Republicans swept the three tossup states where they were playing defense - Kentucky, Georgia, and Kansas.
Braley initially was ahead of Ernst, but he had a number of prominent stumbles during the race. Most notably, he once dismissed the state's other top lawmaker, Sen. Chuck Grassley (R), as "a farmer from Iowa who never went to law school."
Ernst became well known during her Republican primary for an ad touting her experience "castrating pigs" in Iowa farms. Some observers credited the viral ad with her late surge against Braley.