The AP called the U.S. Senate race around 7:40 p.m. Tuesday based on exit polls, saying that Republican John Boozman won.
Lincoln had been considered one of the most vulnerable Democratic incumbents seeking re-election this year. She trailed Boozman in most polls leading up to Tuesday's election.
Lincoln, who chairs the powerful Senate Agriculture Committee, survived a bruising primary and runoff fight for the Democratic nomination. But Boozman, who represented northwest Arkansas in the House, criticized her heavily for supporting President Barack Obama's health care bill.
(Copyright 2010 by The Associated Press. All Rights Reserved.)