In 1992, the federal government told drugmakers they had to give steep discounts to hospitals that treat a large percentage of poor patients. The law got bipartisan support and it was a boon for hospitals and the federal government. In the decades that followed, the discount program has grown by leaps and bounds. But this spring, as the feds have been drawing up new rules for the program, a pitched battle has broken out between hospitals and drug manufacturers who say the program, known as 340B, is bloated and badly regulated.