I didn’t think they could rewrite the entire Constitution, only amend it:
“”The second method prescribed is for a Constitutional Convention to be called by two-thirds of the legislatures of the States, and for that Convention to propose one or more amendments. These amendments are then sent to the states to be approved by three-fourths of the legislatures or conventions. This route has never been taken, and there is discussion in political science circles about just how such a convention would be convened, and what kind of changes it would bring about.
Regardless of which of the two proposal routes is taken, the amendment must be ratified, or approved, by three-fourths of states. There are two ways to do this, too. The text of the amendment may specify whether the bill must be passed by the state legislatures or by a state convention. See the Ratification Convention Page for a discussion of the make up of a convention. Amendments are sent to the legislatures of the states by default. Only one amendment, the 21st, specified a convention. In any case, passage by the legislature or convention is by simple majority.””
http://www.usconstitution.net/constam.html