Topeka ? Gov. Sam Brownback, the billionaire Koch brothers, Kansas Chamber of Commerce and Kansans for Life combined to help defeat a slew of moderate Republican Senate candidates on Tuesday.

Conservative Republicans appeared ready to take over control of the Kansas Senate.

Fueled by huge donations from Wichita-based Koch Industries, and Wichita oilman David Murfin, the Kansas Chamber PAC reported spending nearly $650,000 on conservative candidates in the last 3 1/2 weeks of the campaign.

And that amount didn’t include mailers sent out by Koch-founded Americans for Prosperity, which doesn’t have to report expenditures on its political activity because it is a tax-exempt “social welfare” organization.

Moderates received support from teachers, bi-partisan unions and gaming interests.

Incumbent moderates Senate President Steve Morris of Hugoton, Tim Owens of Overland Park, Roger Reitz of Manhattan, Bob Marshall of Fort Scott, Dwayne Umbarger of Thayer, Pete Brungardt of Salina, Dick Kelsey of Goddard, Jean Schodorf of Wichita and Ruth Teichman of Stafford were defeated Tuesday. Two more conservatives won seats held by moderates who are retiring.

The wins by conservatives are likely to overturn a bi-partisan coalition of moderate Republicans and Democrats in the Senate that has been able to thwart some of Brownback’s agenda.

The bipartisan coalition in the Senate had prevented conservatives from lessening labor unions’ political influence, remaking appellate courts and establishing a 401(k)-style pension plan for new public employees.

Having conservatives in charge of the Senate could mean more restrictions on abortion, anti-labor legislation and a “religious preservation” bill that critics said would have allowed discrimination against gays and lesbians.