In the first ruling by a federal appeals court on President Barack Obama's health care overhaul, a panel in Cincinnati affirmed Wednesday that Congress can require Americans to have minimum insurance coverage.A conservative law center had challenged the measure, arguing on behalf of plaintiffs who said potentially being required to buy insurance or face penalties was subjecting them to financial hardship. They warned that the law was too broad and could lead to more federal mandates.The Thomas More Law Center, based in Ann Arbor, Mich., argued before the panel that the law was unconstitutional and that Congress overstepped its powers.The government countered that the measure was needed for the overall goal of reducing health care costs and reforms such as protecting people with pre-existing conditions. It said the coverage mandate will help keep the costs of changes from being shifted to households and providers.The three-judge 6th U.S. Circuit Court of Appeals panel delivered a long opinion with disagreement on some issues."Congress had a rational basis for concluding that the minimum coverage provision is essential to the Affordable Care Act's larger reforms to the national markets in health care delivery and health insurance," Judge Boyce F. Martin, appointed by former President Jimmy Carter, wrote for the majority in the 2-1 ruling.A George W. Bush appointee concurred; a Ronald Reagan appointee who is a U.S. district judge in Columbus sitting on the panel disagreed. Judges are selected for panels through random draw.An attorney for Thomas More said the center expects to appeal. It could ask for the full circuit court to review the case or go on to the U.S. Supreme Court.More than 30 legal challenges have been filed over the health care overhaul, some focusing on different issues.--Associated Press writer Lisa Cornwell contributed to this report.