In what could be a harbinger of things to come should George W. Bush become president, environmental groups and family farm advocates yesterday unveiled a campaign in which hotshot lawyers from 15 law firms will help them fight pollution from factory hog farms. Taking a page from the tobacco war books, environmental lawyer Robert F. Kennedy, Jr., said that the most effective way to stop corporate pollution during a lax Bush administration would be to file mass tort cases against polluters with the aim of winning huge court-ordered damage awards. The enviros’ pilot case is a lawsuit filed this summer against Smithfield Foods, the nation’s biggest pork producer, for creating a public nuisance by spilling billions of gallons of hog waste into North Carolina rivers. The enviros estimate it would cost $148 billion to cover the damages to 3.7 million acres of wetlands.