Democrats believe that no issue is ever really decided until it is decided in their favor. They will try over and over and over to get the outcome they desire. At which point it is decided for all time and can never be re-visited.
There is a lot of truth in what you say. Democrats NEVER let go of a grudge. If denied something they want they will lie in wait, literally for decades, waiting for the moment to pounce and claim their revenge.