Allina Health doctors picketed in the rain outside four clinics at 6 a.m. Tuesday, hopeful that a show of unity would kickstart their languishing contract talks. Then the doctors hustled off to see patients. The one-hour protest of Allina's Coon Rapids clinic was barely observed by daylight, much less the public, but the recently unionized doctors, nurse practitioners and physician assistants said they had history on their side. The protest was believed to be the first in Minnesota involving doctors engaged in their own union contract dispute.