Protesters hold up placards calling for Congress to kill the Health Care Reform bill during a demonstration on Capitol Hill on March 20. Ten US states plan to file a lawsuit challenging the constitutionality of health care reform as soon as President Barack Obama signs it into law, Florida's attorney general said Monday.(AFP/Getty Images/File/Joshua Roberts)AFP - Ten US states plan to file a lawsuit challenging the constitutionality of health care reform as soon as President Barack Obama signs it into law, Florida's attorney general said Monday.