Romney wins Iowa by 8 votes

Mitt Romney edged Rick Santorum by an eight-vote margin in the closest primary election in modern American history, spotlighting a sharply divided Republican Party headed for an increasingly tough primary battle.

Romney and Santorum were deadlocked from the moment results were released and swapped first and second place throughout Tuesday night. At one point early Wednesday morning, Romney led Santorum by a single vote with 99 percent of precincts reporting. The last tallies weren't announced until around 2:30 Wednesday morning.

Read more of The Hill's coverage of the Iowa caucuses.