Topeka ? One-time rivals, Secretary of State Ron Thornburgh and Sen. Sam Brownback announced Thursday they will work together on Brownback’s bid to be the next Kansas governor.

At an event at Republican party headquarters, Brownback introduced Thornburgh as a campaign co-chairman, praising him for his dedication to the party and the state.

“This party’s coming together, and it’s for the good of Kansas, it’s for the good of the party, and it’s for the good of our future,” said Brownback, a fiscal and social conservative.

He is leaving his seat in the U.S. Senate to run for the open governor’s post. Thornburgh ended his own bid for the GOP nomination for governor this summer and is not seeking re-election as secretary of state.

“It’s not the opportunity that I thought I was going to have this year, but I’m OK with that,” Thornburgh said. “I’m thrilled to be here today.”

Democratic Gov. Mark Parkinson, who took over when Kathleen Sebelius resigned in April to become U.S. secretary of health and human services, has said he will not seek re-election in 2010.

Kenny Johnston, executive director of the Kansas Democratic Party, dismissed Thursday’s announcement, saying an endorsement from Thornburgh doesn’t change Brownback’s image. Brownback has been opposed to abortion, stem cell research, closing the detention center at Guantanamo Bay and President Barack Obama’s efforts to reform health care.

“Sen. Brownback is trying to reinvent himself,” Johnston said. “No matter how many endorsements he gets, Kansas voters won’t forget his extreme record.”

Thornburgh’s endorsement is the second from a prominent, moderate Republican in the past two weeks for Brownback. Insurance Commissioner Sandy Praeger gave her support to Brownback’s campaign on Aug. 28. Praeger is seeking her third term as insurance commissioner after serving in the Kansas Senate.