cast lot in
cast (one's) lot in with (someone or something)
To join another person or become part of a group. Don't worry, Mom—I really don't care about casting my lot in with the cool kids at school.
cast one's lot in (with someone or something)
to join in with someone or a group. He cast his lot in with the others. She cast in her lot with the others. She cast in with a questionable crowd.