WASHINGTON (Reuters) - The U.S. Supreme Court appeared poised on Tuesday to open the door to companies' religious-based objections to government regulations as justices weighed whether business owners can object to part of President Barack Obama's healthcare law. It was unclear whether the companies objecting to the regulation requiring them to provide insurance coverage that includes contraception would win overall, but a majority of the nine justices seemed ready to rule that companies had the same religious rights to object as individuals do. In one of the biggest cases of the year, the court heard an extended 90-minute oral argument,...