Rep. Todd Akin has won the Republican primary for Senate in Missouri, to take on incumbent Democratic Sen. Claire McCaskill.

With 99 percent of precincts reports, Akin has 36 percent of the vote, businessman John Brunner 30 percent, and former state Treasurer Sarah Steelman 29 percent, according to the Associated Press.

McCaskill is widely considered to be one of the most vulnerable 2012 incumbents. The PollTracker Average for the general election match-up currently shows Akin in the lead with 47.7 percent support, compared to McCaskill at 44 percent.