A key part of the Affordable Care Act will be implemented by executive order in Kentucky if the healthcare law is upheld by the U.S. Supreme Court.Exchanges in which residents can purchase insurance are a major part of the law. Each state must have an exchange, and if states don't set them up, the federal government will.Governor Steve Beshear says he will sign an executive order to create a state-run exchange if the law is upheld.Beshear says many state healthcare and business organizations encouraged him to act to allow Kentucky to control its own exchange, which must be active by the end of this year.