U.S. Rep. Todd Akin of Missouri won the Republican nomination to challenge Democratic Sen. Claire McCaskill, a vulnerable incumbent whose seat is key to GOPhopes for taking control of the chamber.

A six-term congressman, Akin edged out former state Treasurer Sarah Steelman and businessman John Brunner in a tight race that divided tea party activists.

But Akin may have gotten the key boost from an unlikely figure: McCaskill.

Preferring to square off against a candidate with his own record in Washington, McCaskill helped generate enthusiasm for Akin when she aired an ad branding him “Missouri’s true conservative.”


Akin had been endorsed by former Arkansas Gov. Mike Huckabee and Minnesota Rep. Michele Bachmann. Steelman had the backing of former Alaska Gov. Sarah Palin and the Tea Party Express. Another tea party group, FreedomWorks, had supported Brunner.

By late Tuesday night, with more than 80% of precincts reporting, Akin had 36% of the vote. Steelman and Brunner each had less than 30%.

Akin enters the general election with a slight advantage. A St. Louis Post Dispatch-Mason Dixon poll taken in late July has him beating McCaskill 49% to 44% in a hypothetical matchup.

The race is sure to be among the most expensive Senate contests this cycle. Already, more than $15 million has been spent on attack ads targeting McCaskill, and Democratic ad trackers expect that figure to reach $33 million by November.


McCaskill is considered the most endangered Democratic Senate incumbent, and she’s running in a state that has been tilting Republican.

She won the seat in 2006 on a Democratic wave that gave the party control of both the House and Senate.

But in 2008, Missouri went for John McCain for president. President Obama lost by fewer than 4,000 votes, but the state is barely considered a battleground for 2012. Obama has not campaigned there, to McCaskill’s dismay.

Democrats appeared eager to move on from the primary process and get to work branding Akin as a radical who can’t appeal to the more moderate voters who will be key to deciding the race in November.


“Now this race changes,” Democratic Senatorial Campaign Committee Executive Director Guy Cecil said in a statement. “Tonight’s results provide Missourians with a crystal-clear choice between Todd Akin’s tea party policies and Claire McCaskill, a moderate and independent leader who fights for middle-class Missourians.”

McCaskill wasted no time in using the news to tap supporters for more campaign cash. Shortly after the race was called, an email from McCaskill’s campaign warned that Republicans had nominated “one of the most fringe, conservative congressmen in the United States,” as it urged supporters to make a donation to the campaign.

kim.geiger@latimes.com