More than 100 current and former Republican officials endorsed Democratic state Rep. Paul Davis's bid to unseat Gov. Sam Brownback (R) Tuesday, marking a new setback for the incumbent, who was already facing a competitive reelection campaign.

A mass defection like this is not typically seen in statewide campaigns. It signaled the tough road ahead Brownback could face as the November election approaches.

The collection of Republicans, dubbed "Republicans for Kansas Values," endorsed Davis's bid at an event in Topeka. They oppose Brownback for a laundry list of reasons, including tax cuts he spearheaded, cuts to education spending and his alienating some centrist members of the GOP.

The Republicans include state legislators, mayors and delegates to Republican National Convention, among others.

"The decision to endorse a Democratic candidate for governor is a big step for all of us and a major departure from our Republican roots. We do not make this decision lightly," said former state Senate president Dick Bond. "But this election should not be about electing a Republican or a Democrat as Governor. It must be about electing a moderate, commonsense Kansan as governor."

Recent polls have shown a competitive race between Brownback and Davis, who are expected to win their respective party nominations next month.

In response to the endorsements, a spokesman for the governor's reelection campaign cited job creation and education statistics as evidence of Brownback's first-term success.

“Under Governor Brownback’s leadership Kansas has created 53,400 new private sector jobs, Kansas kids have 676 more certified teachers in the classroom, and recently provided $84 million in property tax relief for hard working families," said Brownback spokesman John Milburn.