The Kansas House endorsed a proposed Constitutional Amendment Friday that would prohibit the federal government from requiring Kansans to purchase health insurance. That mandate is a key provision in the new federal health care law. Missouri voters passed a similar Amendment last fall. Friday's House vote was 91-27. Now the measure goes to the Senate. Constitutional amendments require a two-thirds vote in each chamber. The proposed amendment failed in the Senate last year. If it passes, the proposed constitutional change would go on the November 2012 ballot.