Missouri Democrat Claire McCaskill defeated Republican Sen. Jim Talent in one of the nation's most closely contested Senate races, significantly boosting Democratic hopes of seizing control of the chamber from Republicans.

Talent told supporters early Wednesday he had called McCaskill to congratulate her. McCaskill, meanwhile, declared to a cheering crowd: "You elected an underdog because you believed you could."

With 89 percent of precincts reporting, McCaskill was declared the winner. The call for McCaskill was based on a number of factors, including voter turnout, previous voting patterns, and a statistical analysis of the vote from voter interviews conducted for The Associated Press by Edison Media Research and Mitofsky International.

McCaskill had roughly 906,000 votes to Talent's 875,000 — a margin of a little less than 2 percentage points, with some votes still remaining to be counted.

"Tonight we have heard the voices of Missourians and they have said we want change," McCaskill declared.

The war in Iraq and several high profile ballot issues — especially one engraving the right to conduct embryonic stem cell research into the Missouri Constitution — played a prominent role in the Missouri Senate race.

McCaskill called for a redeployment from Iraq within two years and prominently supported the stem cell initiative. Talent opposed the amendment, saying it would allow the cloning and destruction of early human life, and tried to characterize McCaskill as weak on terrorists.

Talent had expressed frustration about having to run against voter discontent with President Bush and scandals involving other Republican officials.

"It was not for the lack of effort. The headwind was just very, very strong this year," Talent told his subdued crowd of supporters.

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