Democratic state Sen. Troy Jackson says money is the reason that a major environmental group has endorsed his opponent in the 2nd District congressional primary, and is targeting him. The League of Conservation Voters is supporting state Sen. Emily Cain, and criticizing Jackson's environmental voting record, in a series of mailers to voters in the district. Jackson says one of Cain's financial backers in Maine, R. Donald Sussman, gave a big contribution to the League to help fund the $150,000 campaign. But an official with the organization says Sussman had nothing to do with the mailers, and that the real issue is Jackson's record.