WASHINGTON - Sen. Barack Obama got a front-runner's welcome back at the Capitol Thursday, pressing congressional "superdelegates" to support him in a visit that had the look and feel of a campaign victory lap. On the House floor, he was quickly surrounded by well-wishers calling him, "Mr. President" and reaching out to pat him on the back or shake his hand. The glad-handers included a few Republicans and supporters of his Democratic presidential rival, Hillary Rodham Clinton. He picked up the superdelegate support of at least two lawmakers: Rep. Brad Miller of North Carolina, where Obama handily won the primary...