Washington Post: House Democrats introduced an ambitious climate bill yesterday aimed at pleasing both environmental and business interests, even as Senate leaders acknowledged that the party faces serious challenges in trying to pass a carbon limit in the near future. The 648-page "discussion draft," crafted by House Energy and Commerce Chairman Henry A. Waxman (Calif.) and Rep. Edward J. Markey (Mass.), chairman of the subcommittee on energy and the environment, would create the first federal …