Conservative congressman Todd Akin has won a tough three-way Republican primary for Senate in Missouri, the Associated Press reports. In a race that had been close between Akin, businessman John Brunner, and former state treasurer Sarah Steelman, the seven-term representative from northeastern Missouri pulled ahead with more than 36 percent of the vote. Polls showed the primary remained tight just days before the election, and each candidate had support for major conservative figures and groups.

Akin will face incumbent Democratic senator Claire McCaskill in the general election in what may be the Democrats' toughest Senate race this November. McCaskill was unopposed in Tuesday's Democratic primary.

In polls taken prior to Tuesday's primary, Akin was the weakest of the three Republican candidates against McCaskill, though the RealClearPolitics average shows he still leads her by three points. McCaskill, who won a close race over Republican Jim Talent in 2006, is vulnerable in a state like Missouri, which has been trending Republican in recent years. The Show Me State is likely to vote for the Republican presidential candidate over Barack Obama, as it did in 2008, which could benefit Akin in the Senate race.