The National Association of Manufacturers has begun targeting Senators in seven states on cap-and-trade legislation that awaits the Senate when it returns in less than two weeks.The trade group on Thursday announced a multimillion dollar television, radio and Internet advertising buy in Indiana, Michigan, Missouri, Nebraska, North Dakota, Ohio and Virginia. Each of those states is represented by one, or in some cases two, Senators who are viewed as swing votes on the climate change bill.One of the likely targets, Sen. Claire McCaskill (D-Mo.), has acknowledged she has some reservations about the legislation."I hope we can fix cap and trade so it doesn't unfairly punish businesses and families in coal-dependent states like Missouri," she wrote on her Twitter page earlier this summer.NAM officials on Thursday afternoon said other states may be added in the coming weeks and declined to indicate the initial ad buy's price tag.The House narrowly passed cap-and-trade legislation earlier this summer, 219-212. The contentious legislation would set pollution levels and create a private marketplace for the sale of offsets.The Senate Energy and Natural Resources Committee may take up its version of the climate change bill after returning in September.