WASHINGTON -- An effort by House Republicans to highlight problems with President Barack Obama's health care law by bailing out a program for people with pre-existing medical conditions appeared to backfire Wednesday. GOP leaders postponed a scheduled vote after the measure met strong opposition from two directions: from conservative groups resistant to any federal role in health care and from Democrats who objected that the Republicans planned to pay for the high-risk patient program by raiding a disease prevention provision the administration says is essential to the overhaul.