What gave the puritans in Massachussettts Bay Colony the right to elect their own leaders??

Question

I forget my social studies books at school!!!!

Answer 1

The USA did not exist at the time and they gave themselves the right to elect their own leaders.
That's why they migrated here from Europe where they did not have such rights.

Answer 2

It is part of the royal charters. For instance, I copied a piece from the royal charter for Maine (which was part of Massachussetts before hand):

whose names are expressed in ye said Letters Patents, and their successors and assignee, that they shall be one Body Politique and Corporate perpetuall, and that they should have perpetual succession, &c., and one comon scale or scales, to serve for the said Body, and that they and their successors shall be known, called and incorporated by the name of the President and Councill established at Plymouth in the county of Devon, for the planting, ruling and governing of New-England in America

King James expected that they have a body for the "ruling and governing of New-England in America".