Washington-The precedent-shattering merger of America Online, Inc., and Time Warner is expected to face tough scrutiny from regulators and lawmakers.

Already, Senate Judiciary Committee Chairman Orrin Hatch, who is vying for the Republican presidential nomination, has said the $160 billion deal raises “profound public policy implications” and that his committee would study the merger closely. “We need to proceed with a degree of caution to ensure that potential antitrust concerns, if any, are properly addressed.”