Demigods: Demigods and Pure devotees

                                                                  Q. In the Krishna Book, Chapter 4, where the counselors of Kamsa give instructions to him, they give some examples of the demigods being very much afraid of the demons. They also talk about the demigods surrendering and begging for their lives with folded hands. How could this have happened? Don't the demigods have a higher perception of Krishna? Doesn't Krishna protect the demigods? Doesn't goodness overcome evil?