Proposes to amend the Legislature and Revenue Articles of the Illinois Constitution. Provides that the General Assembly may increase the rate of an existing tax or impose a new tax only by a law approved by the vote of two-thirds of the members elected to each house. Provides that the General Assembly may override the veto of the Governor of a bill to increase the rate of an existing tax or impose a new tax only by a record vote of two-thirds of the members elected to each house. Effective upon being declared adopted.