Factbox: Obama's Clean Power Plan faces tough legal scrutiny

By Lawrence Hurley WASHINGTON (Reuters) - The final version of the U.S. Environmental Protection Agency's Clean Power Plan, which aims to curb carbon emissions from power plants, is scheduled for release on Monday. Here are some questions and answers about how the legal fight could unfold: Q: Challengers are first expected to ask a federal appeals court in Washington to block the regulation from taking effect until litigation is complete. A: It is relatively rare for the U.S. Court of Appeals fo