President Bush is poised to change course and announce as early as this week that he wants Congress to pass a bill to combat global warming, and will lay out principles for what that should include. Specifics of the policy are still being fiercely debated, but Bush administration officials have told Republicans in Congress that they feel pressure to act now because they fear a coming regulatory nightmare. It would be the first time Mr. Bush has called for statutory authority on the subject. "This is an attempt to move the administration and the party closer to the center on...