His mother's brothers spoke of him in the ears of all the men of Shechem all these words: and their hearts inclined to follow Abimelech; for they said, He is our brother.
In other words, he's an outsider. We ought to be serving Hamor and his family, let them be the kings. And he said to God the people were under my rule, because I can really do a good job here, you know. Who's Abimelech? And so he said if you would just commit yourself to me I would remove Abimelech.