Further limitations on local powers of taxation and indebtedness

§ 12. It shall be the duty of the legislature, subject to the\nprovisions of this constitution, to restrict the power of taxation,\nassessment, borrowing money, contracting indebtedness, and loaning the\ncredit of counties, cities, towns and villages, so as to prevent abuses\nin taxation and assessments and in contracting of indebtedness by them.\nNothing in this article shall be construed to prevent the legislature\nfrom further restricting the powers herein specified of any county,\ncity, town, village or school district to contract indebtedness or to\nlevy taxes on real estate. The legislature shall not, however, restrict\nthe power to levy taxes on real estate for the payment of interest on or\nprincipal of indebtedness theretofore contracted.\n