WASHINGTON -- President Barack Obama has chosen a suburban St. Louis high school to make his closing argument for a health care overhaul, pushing a new anti-fraud plan as he cranks up the pressure on skittish Democratic lawmakers to act fast.

Obama is to speak Wednesday at St. Charles High School, his second health care address in three days. His speech comes as congressional Democrats stand on the brink of delivering the president a success with passage of his sweeping overhaul legislation -- or a colossal failure if they can't get it done.

Business groups that oppose the legislation are also stepping it up, with the U.S. Chamber of Commerce announcing a coordinated campaign to spend as much as $10 million on ads, starting Wednesday, saying, "Stop this health care bill we can't afford."

Leaders in the House and Senate are waiting for a final cost analysis from the Congressional Budget Office in the next day or so that will allow them to start counting votes -- and twisting arms -- in earnest. In the House, in particular, getting the needed majority will be touch and go....