By Carey Gillam
KANSAS CITY, Missouri (Reuters) - A congressman from Missouri won his state's Republican nomination on Tuesday, setting the stage for a challenge to U.S. Senator Claire McCaskill, who political analysts consider the most vulnerable Democratic incumbent in the country this November.
Besides Missouri, voters in Michigan and Washington also were picking U.S. Senate candidates on Tuesday. Republicans need a net gain of four seats in the November 6 general election to take control of the Senate.
Missouri Congressman Todd Akin thanked "God our Creator" for blessing his campaign in a victory speech. With about 91 percent of precincts reporting, Akin had 36 percent of the vote, St. Louis businessman John Brunner about 30 percent and former state Senator Sarah Steelman 29 percent.
"The choice is clear in November," Akin said in a statement on Tuesday night. "The big spending, budget-busting, job-killing liberal or the less spending, balanced budget, job-creating conservative."
McCaskill, who is struggling in a state that has gone increasingly Republican after being a bellwether in presidential elections for a century, wasted no time in responding.
"Throughout the primary campaign, Akin repeatedly gave voice to positions that show how extreme he is, and how willing he would be to throw middle-class families under the bus to protect tax breaks for the mega-wealthy and tax giveaways to Big Oil," McCaskill said in a statement.
McCaskill's support of Democratic President Barack Obama's healthcare reform has hurt her, said Steve Glorioso, a political consultant who has worked on past McCaskill campaigns.
Brunner had never run for political office and bankrolled his own campaign to join a string of conservative newcomers who have challenged established Republicans but Brunner came up short.
Others have upset traditional Republicans in Indiana, Nebraska and Texas and are running strong races in Arizona and Wisconsin.
The once-a-decade rewriting of Missouri's Congressional districts also forced incumbent Democratic Representatives William Lacy Clay and Russ Carnahan into a primary fight, won by Clay.
In Michigan, former Congressman Peter Hoekstra easily won the Republican nomination over his next closest competitor, Clark Durant, who was endorsed by the Tea Party Express. Candidates Randy Hekman and Gary Glenn trailed.
Hoekstra faces incumbent Democratic U.S. Senator Debbie Stabenow, who has led any of the potential Republican challengers comfortably in recent polls.
Hoekstra's first campaign ad this year was criticized as racist because it featured an Asian woman on a bicycle speaking broken English in an attempt to accuse Stabenow of selling out U.S. interests to China.
Washington state's primary advances the top two candidates in the vote count to the November election rather than holding separate Republican and Democratic primary elections.
Incumbent Democratic U.S. Senator Maria Cantwell progressed to the November election with more than half the vote and will face Republican state Senator Michael Baumgartner, who took about 30 percent of the vote in a crowded field of challengers.
In Kansas, there is no U.S. Senate election this year and the four Republican incumbents in the House sailed through the primary.
There is a real battle in Kansas at the state level between Republicans. Conservative Republicans were scoring key victories across the state, in rural areas and metropolitan suburbs, strengthening their position in the state Senate and that of conservative Governor Sam Brownback.
(Additional reporting by Greg McCune in Chicago, Kevin Murphy in Kansas City, Nicole Neroulias in Seattle and David Bailey in Minneapolis; Editing by Vicki Allen and Lisa Shumaker)