Tenet Healthcare Corp. made a new case Tuesday for why a bid from Community Health Systems Inc. falls short of its value, arguing that improving patient volume trends, benefits from the healthcare overhaul law and existing strategic initiatives will generate strong growth. Tenet has rejected Community's offer, which is $3.3 billion plus the assumption of $4 billion in debt. Ramping up the battle, it recently adopted a "poison pill" takeover defense plan. Community, for its part, has said it plans to nominate a slate of directors to Tenet's board. Community CEO Wayne T. Smith said at an investor conference that the company believes its offer is "very attractive" and is "in this for the long haul, we're here to stay."