We, too, have raccoons (1 or more) in the yard virtually every night. They rattled the door a few times about a year and a half ago, and to my knowledge have not bothered the coop since. They raid my birdseed every night, and that's OK with me, since they leave the girls alone. Whenever there is enough snow to track their prints around the yard, I have NEVER seen those prints near the coop.
However, we lock up the chickens every night, and we have a baby monitor in the coop. I don't say that the raccoons will NEVER try, but we are prepared for that too, so we rather enjoy our birdseed bandits. Some nights they come right up to our bedroom window on the deck roof!