“After much thoughtful reflection, a run for governor is not meant to be,” Thornburgh said in a press release.

Thornburgh had earlier announced his intention to run for the Republican Party nomination. U.S. Sen. Sam Brownback, R-Kan., is also running for the GOP nod.

In a recent poll, Brownback, who is considered a leading conservative Republican, had a commanding lead over Thornburgh.

Thornburgh’s news release didn’t mention Brownback.

“The decision to run centered on our strongly held conviction that core Republican principles of lower taxes, less government, individual responsibility and accountability return to the Governor’s office,” Thornburgh said.

“It is more important for the ideas and ideals that I believe in to win in November than for me to run. Our priority is the next generation of Kansans – not the next election,” he said.

The current governor, Mark Parkinson, a Democrat, was recently elevated to the job after Kathleen Sebelius left office to become U.S. secretary of health and human services. Parkinson, who had served as Sebelius’ lieutenant governor, has said he will not stand for election as governor.

No other Kansas Democrat has stepped forward. With Thornburgh bowing out, it appears more likely that Brownback will win the GOP nomination.