In a tight Senate race with national implications, Democrat Claire McCaskill defeated incumbent Missouri Republican Sen. Jim Talent.
"The Democratic Party once again has claimed Harry Truman's Senate seat for the working people of Missouri," McCaskill declared.
Talent took an early lead over McCaskill, the state auditor, in one of the nation's most closely contested races, but that lead disappeared by 1 a.m.
"Tonight we have heard the voices of Missourians, and they have said we want change," McCaskill, 53, said in her victory speech.
Two years earlier, McCaskill had run for governor, losing by more than 80,000 votes, her first defeat in nearly two decades of public life.
Her race against Talent ground along in a dead heat for two months, but last night she made huge gains in St. Louis County, home to one-fifth of the state's votes. The last Democrat to run for Senate won the county by 15,000 votes. McCaskill won by more than three times as many votes.
Voter turnout was heavy across the state, an estimated 10 percent higher than the last midterm election. St. Louis political scientist Terry Jones attributes the turnout to a controversial ballot amendment protecting embryonic stem-cell research. The most galvanizing issue at the poll, the stem-cell amendment narrowly passed.
McCaskill also attributed her win to voter disenchantment with President Bush and the war in Iraq. In Talent's concession speech, he seemed to suggest the same.
"It was not for the effort, it was not because of any lack of support," Talent told subdued supporters. "You all did a great, great job. The headwind was just very, very strong this year."