You shall make no covenant with them and their gods. They shall not remain in your land, lest they cause you to sin against Me; for you will serve their gods - and it will prove a snare to you.
I was recently asked by someone I very much respect to address "the" question. So I started to write the answer in a post... about five times without any luck. The "Why does a 20-something join a Reform Congregation" question.
Asher did not dispossess the inhabitants of Acco or the inhabitants of Sidon, Ahlab, Achziv, Helbah, Aphik, and Rehob. So the Asherites dwelt in the midst of the Canaanites, the inhabitants of the land, for they did not dispossess them.