The head of the state’s firefighters union promises to bring principles that guide his profession to state government if voters elect him Wisconsin’s next governor. Mahlon Mitchell, who last week joined the crowded Democratic field of candidates hoping to unseat GOP Gov. Scott Walker, brought his high-energy campaign to Eau Claire on Monday and sprinkled firefighting analogies throughout his 20-minute speech to about three dozen supporters at The Oxbow Hotel. A centerpiece of his gubernatorial campaign is a mantra that guides firefighters — “All hands working” — that Mitchell explained means everybody at the scene of an emergency works as a team to do something to make the situation better.