Immigration does not fall under the domestic policy. A domestic policy differs from foreign policy, which refers to the ways a government advances its interests in world politics.
It helped them farm and to grow crops. They needed this to live and to trade. It had a good source of water and could be used to drive enemies away from them.
They affect how people react and stuff like that
To force a bill out of the committee, a discharge petition must be signed by a majority of the representatives.