The Journal Sentinel quotes Gilkes as having said to an Associated Press reporter:

As we see activity on the Democrats' part, on the public-sector employees' part, talking about running campaigns against the governor, we want to ensure our message is being heard. We want to make sure we're prepared for anything they may attempt against the governor whether now, a year from now or three years from now.

Gilkes also said that his resignation is unrelated to an ongoing John Doe investigation by the Milwaukee County District Attorney. That investigation has already reached into the highest levels of the Walker administration. His top aide in the Department of Administration resigned in August and was assigned a job in another state agency. She is on paid medical leave and has not yet reported to her new position. The FBI assisted with the execution of a search warrant on her Madison home recently and confiscated computer hard drives and other materials.

It was also learned recently that Walker's spokesperson and two other Walker associates have been given immunity from prosecution in the John Doe probe.

This resignation smells. Walker's chief of staff resigns a $112,000 per year post to go back to being self-employed and prepare for something that might happen up to three years from now. The resignation is announced on a Friday afternoon when Madison media are devoting massive coverage to Saturday's University of Wisconsin - University of Nebraska football game (Nebraska's first game ever in the Big 10 conference.)

We're supposed to believe it has nothing to do with an investigation of Walker's gubernatorial campaign, which Keith Gilkes managed before becoming Walker's Chief of Staff.

Uh huh. And I have 4 tickets to Camp Randall Stadium on the 50 yard line that I'll give away if anybody wants them.