Power - for what?
Abimelech seized the opportunity of his father's death to go to his mother's family in Shechem with a request: "Say this in the hearing of all the lords of Shechem - Which will be better for you, that all seventy sons rule over you or that one rule over you? Remember that I am your bone and flesh." They gave him money to hire hit-men. The seventy were murdered, all but Jotham, the youngest, who escaped. Abimelech was made king.
One day Jotham appeared suddenly on a promontory above Shechem, and spoke to the people below in a parable:
The trees went forth to anoint a king. To the olive, so plentiful in the fertile valley, they said, "Reign over us!" "But I already produce rich oil by which gods and mortals are honoured. Why should I leave that to rule over the trees?""What is it like then," Jotham asked, "to be with Abimelech? Is it action of good faith, as with his father Jerubbaal, or is it fire?" Unchecked, the bramble takes over. The assumption of power carries responsibility.
Then they said to the fig tree, "You come and reign over us!" "Should I leave my sweetness for the sake of holding authority over the trees?"
They approached the vine: "You reign over us!" But the vine replied, "Should I stop producing wine that cheers gods and mortals in order to rule the trees?"
So at last they turned to the bramble that clings to the rocks round Shechem. "Will you be our king?" With alacrity the bramble replied: "If you mean to make me king, come and take refuge in my shadow. But if not, let fire break out in the dried up thorn and spread even to the cedars of Lebanon!"
The fire came. Conflict between Abimelech and the leaders of Shechem reached the city gate. Abimelech took Shechem and slaughtered its people. The city was razed and sown with salt. When some leaders made for the stronghold of the temple of El-berith nearby, Abimelech set it on fire. But when he tried to do the same thing at Thebez a woman dropped a round millstone from the top of the tower onto his head. As he lay dying, Abimelech ordered a young man to use his sword, lest it be said that a woman killed him.
There is a postscript. In the experience of Israel kingship proved disappointing, and authority so corrupt that they looked back in nostalgia to the days when 'there was no king in Israel. All the people did what was right in their own eyes.'