Kansas Secretary of State Ron Thornburgh has ended his bid in the state's 2010 contest for governor, giving retiring Sen. Sam Brownback a clear path to the GOP nomination.

The development also solidifies Brownback's status as the front-runner in the race for the seat -- currently held by interim Democratic Gov. Mark Parkinson -- as he will be spared a primary contest with a well-known and longtime statewide officeholder. Thornburgh has been secretary of state since he was first elected in 1994.

Nonetheless, Thornburgh would have needed a major come-from-behind push to overcome Brownback, who first won his Senate seat in a 1996 special election, won landslide re-election victories in 1998 and 2004, and ran a short-lived campaign for the 2008 Republican presidential nomination. A recent poll conducted by SurveyUSA showed Brownback trouncing Thornburgh by a margin of 47 percentage points.